Fees are rarely made public, so where a confirmed price is not available, an estimate has been made from an assessment of all available data.

30 MATTHEW HOPPE

(From Real Mallorca, August 2022, £2.5m)

Hoppe arrived from Real Mallorca in the summer of 2022, with Boro shelling out a transfer fee of around £2.5m at a time when they were not really spending that kind of money on established performers, let alone untried youngsters. Described as a “development signing” by Chris Wilder, Hoppe looked out of his depth from the start. His three years at Boro brought six senior starts, featured loan spells at Hibs and San Jose Earthquakes, and came to an ignominious end when his contract was cancelled by mutual consent in January.

29 MICAH HAMILTON

(From Man City, Aug 2024, £2m)

When Boro prised Hamilton from the youth ranks at Manchester City last summer, they thought they had secured a real bargain. There is still time for their judgement to be proved correct given that the 21-year-old is contracted to the Riverside until 2028. Hamilton struggled in the first half of last season though, failing to make an impact on Boro’s first team, and more worryingly, couldn’t force his way into the Stockport team during a loan spell in League One in the second half of the campaign.

28 SAMMY SILVERA

(From Central Coast Mariners, Jul 2023, £800,000)

Boro had high hopes for winger Sammy Silvera when they signed him from his native Australia for around £800,000 in the summer of 2023. He made 37 league appearances during his first season on Teesside – 25 of which were from the bench – but was deemed surplus to requirements under Michael Carrick last summer.  A subsequent loan spell at Portsmouth was something of a disaster, and Silvera spent most of the second half of last season on the substitutes’ bench at League One Blackpool.

27 CAOLAN BOYD-MUNCE

(From Birmingham, Jan 2022, £300,000)

The first signing made under the current recruitment regime that involved a transfer fee, Boyd-Munce was plucked from Birmingham’s youth ranks and handed a two-and-a-half year deal. He scored on his debut in an FA Cup win over Mansfield, but made just three more senior appearances as a Boro player. His contract was terminated by mutual consent in January 2023, and he will spend next season with League One Wycombe after signing a contract with the club last month.

26 ALEX GILBERT

(From Brentford, Jul 2023, £1m)

Gilbert had been playing for Brentford’s B team prior to moving to the North-East, but Boro still paid around £1m to secure his services. So far, it’s hard to say that it was money well spent. Gilbert has made 25 senior appearances for Boro, and looked like he was forcing his way into the first-team picture when he was handed a run of games at the end of the 2023-24 season. He barely featured at all last season though, and was loaned out to League One Charlton for the second half of the campaign.

25 MASSIMO LUONGO

(Unattached, Sep 2022, Free)

Signed as a free agent to plug a short-term gap at the heart of midfield, Luongo was handed a three-month contract when he signed in the wake of his release from Sheffield Wednesday the previous summer. He didn’t make a single appearance as a Boro player though, with his contract being cancelled in January 2023 to enable him to move on to Ipswich Town. Given how well he played at Portman Road in the next couple of seasons, it could definitely be argued that Boro missed out.

24 JAMIE JONES

(From Wigan, Jul 2023, Free)

Jones was signed on a one-year contract in the summer of 2023 following the end of his previous deal at Wigan, even though Boro’s goalkeeping department already looked to be well stocked. The veteran didn’t make a single senior appearance during the 2023-24 season, but Boro were considering offering him a new deal last summer before he instead opted to move to League Two side Salford City, where he was number one for most of last season.

23 NEIL TAYLOR

(Unattached, Nov 2021, Free)

Taylor was the first player signed during Scott’s reign as head of football, with the left-back arriving as a free agent in November 2021, having been without a club for three months. He was initially signed on a two-month deal, but his contract was extended when Marc Bola suffered a serious knee injury. He made 17 starts under Chris Wilder during the 2021-22 season, but was released at the end of the campaign, at which he announced his retirement.

22 LIAM ROBERTS

(From Northampton, Jun 2022, Free)

When Roberts joined Boro in the summer of 2022, having turned down the offer of a new deal at his previous club, Northampton, he backed himself to secure a regular starting spot under Chris Wilder. However he made just five senior appearances before he was eventually forced to admit defeat and leave as a free agent following a loan spell at Barnsley. He moved on to Millwall, where he earned notoriety last season for a flying challenge on Jean-Phillipe Mateta in the FA Cup.

21 LUKAS ENGEL

(From Silkeborg, Aug 2023, £1.5m)

Engel had been playing in the Danish top-flight with Silkeborg when Boro decided to spend around £1.5m to bring him to Teesside. His Boro career had an extremely shaky start – he was hauled off at half-time after an especially torrid time at Hillsborough – and while he gradually settled, he fell out of favour in the 2024-25 season and was loaned to MLS side FC Cincinnati in February. He has been a regular at left-back with Cincinnati, starting 20 MLS games.

20 MORGAN WHITTAKER

(From Plymouth, Jan 2025, £5m)

These are still early days for Whittaker at Boro, but given that he is the most expensive signing of the last four years with a price tag of around £5m, it is safe to say that the winger has not yet lived up to expectations. He was a regular goalscorer and creator at Home Park, but despite making 16 first-team appearances for Boro in the second half of last season, he is yet to open his goalscoring account for the club. Hopefully, that will change under new boss Rob Edwards next season.

19 DELANO BURGZORG

(From Mainz, Jun 2024, £2.5m)

Burgzorg’s transfer fee of around £2.5m makes him one of the more expensive players on this list, so while the Dutchman might have had some decent moments last season, he failed to quite deliver the kind of consistent excellence that might have been hoped for. He made 25 Championship appearances last season, scoring three goals, and spent most of his time in a wide-attacking role on the left. It will be now be interesting to see what role he plays under Edwards next season.

18 ALEX BANGURA

(From SC Cambur, Sep 2023, £1m)

What would Bangura have achieved with Boro had he not suffered a serious Achilles injury in pre-season last summer that ruled him out of the whole of last season? The left-back had shown glimmers of promise during his first year on Teesside, even if a previous injury issue meant he was only able to make 18 senior appearances in a Boro shirt. He is back to full fitness now, though, so perhaps next season will see him finally stay fit and deliver on his potential.

17 TOM GLOVER

(From Melbourne City, Jul 2023, Free)

When Glover arrived from his native Australia in the summer of 2023,  most observers expected him to have to play a supporting role within Boro’s goalkeeping ranks. That is the way things have gone for most of his time in England, but his fortunes changed when an injury to Seny Dieng saw him promoted to the starting side last December. Within eight games he was back on the bench, though, with some shaky displays seeing him fluff his chance to make a positive impression.

16 NETO BORGES

(From Clermont, Aug 2024, £1.3m)

Boro’s search for a new left-back last summer took them to French club Clermont, and the signing of Borges. The Brazilian signed a three-year deal, and enjoyed a solid enough season, moving ahead of Lukas Engel in the pecking order and making 34 league starts under Carrick. He will hope to be even more influential under Edwards next season, and could even find himself being considered for a centre-half role in the new Boro boss opts to play with three central defenders.

15 GEORGE EDMUNDSON

(From Ipswich, Aug 2024, £600,000)

Edmundson initially signed on loan from Ipswich last summer, and his performances in the first half of the season at centre-half persuaded Boro to seek a permanent transfer in the January window. After some negotiating with Ipswich, a fee of around £600,000 was agreed, but Edmundson found himself struggling for game time in the second half of the campaign and failed to feature in any of the final 13 matches of last season. With Boro reasonably well-stocked at centre-half, it already feels like he has an uncertain future under Edwards.

14 TOMMY SMITH

(From Stoke, Jul 2022, Free)

Signed on a free contract following his release from Stoke City in the summer of 2022, Smith made the right-back spot his own during his first season as a Boro player, starting 31 league games. He fell out of favour at the start of the following campaign, and was rocked by a ruptured Achilles in October 2023 that would prematurely end his season. After 15 months of treatment and rehabilitation, Smith called time on his career in February.

13 DAN BARLASER

(From Rotherham, Jan 2023, £800,000)

Has Barlaser’s transfer from Rotherham been a success or failure? Probably neither. Signed for less than £1m, the 28-year-old central midfielder has made 79 senior appearances, some of which have seen him reproduce the kind of incisive passing displays that made him such an key creative presence at his previous club. However, he has never really been able to hold down a regular spot at the heart of the Boro midfield and for every good performance, there has also tended to be an ineffective one.

12 MARCUS FORSS

(From Brentford, Jul 2022, £3m)

Boro’s £3m investment in Forss back in the summer of 2022 was a fairly significant vote of confidence in the Finnish striker, who had just completed a loan spell at Hull City. You couldn’t say the 26-year-old has been an unqualified success on Teesside, but he has had his moments, and things might well have been much better had injuries not intervened. Forss has scored 18 goals in 90 appearances in a Boro shirt – almost half of which have been as a substitute – with his role varying between that of a wide attacker and a central striker.

11 MATT CLARKE

(From Brighton, Aug 2022, £2.2m)

It looked as though Clarke’s Boro career was going to be over before it had begun when he suffered a back injury just six games in, with the problem eventually sidelining him for 14 months. He came back strongly in the second half of the 2023-24 season, starting pretty much every game at the heart of Carrick’s back four, and there was a fair degree of surprise when Boro opted to sell him to Derby last summer. The sale did, however, enable them to recoup pretty much all of the sum they spent on him two years earlier.

10 DARRAGH LENIHAN

(From Blackburn, Jun 2022, Free)

Darragh LenihanBoro fought off competition from a host of Championship clubs to sign Lenihan as a free agent in the summer of 2022, and the Irishman was a major influence during his first season on Teesside, both on and off the field. He looked set for another impressive season when he suffered a serious ankle injury in October 2023 that would subsequently sideline him for the best part of two seasons. Boro missed his defensive leadership in his absence, but he is finally back fit, with Edwards having been keen to talk him up at a talk-in with fans this week.

9 SENY DIENG

(From QPR, Jul 2023, £2m)

He has had his wobbly moments in a Boro shirt, generally when trying to play the ball out from the back, but Dieng’s £2m switch from QPR still has to be regarded as a success. The Senegal international was the clear number one for the vast majority of Carrick’s reign, starting 52 games, and would almost certainly have remained unchallenged had he not suffered an Achilles injury that ended his campaign in January. It remains to be seen when he will be able to return to the side.

8 LUKE AYLING

(From Leeds, May 2024, Free)

Ayling was a cult hero at his previous club, Leeds United, and while he hasn’t quite achieved that level of acclaim at Boro, he has more than endeared himself to the Riverside faithful during the last season-and-a-half. Initially signed as a loanee in January 2024, Ayling did so well during his first four months on Teesside that he earned himself a permanent move. He struggled with injuries last season, but still racked up 28 appearances in his preferred right-back spot.

7 TOMMY CONWAY

(From Bristol City, Aug 2024, £4.5m)

He is only a quarter of the way through the four-year contract he signed when he joined Boro from Bristol City, so there is every chance there is still a lot more to come, but Conway has made a more-than-decent start to his career on Teesside. He scored 13 league goals last term, a reasonably impressive return given that Carrick’s side underperformed for much of the campaign. Boro will almost certainly sign at least one more striker this summer, but Conway will almost certainly remain a key figure under Edwards next season.

6 FINN AZAZ

(From Aston Villa, Jan 2024, £2.5m)

Boro acted decisively to sign Azaz from Aston Villa in January 2024, cutting short a loan spell at Plymouth in order to push through a deal for the Irish international. The last year-and-a-half has highlighted why they were so keen to move for the midfielder, with Azaz having been Boro’s key creative presence on a regular basis. His tally of 11 Championship assists last season put him in the top five players in the league, sparking speculation over a possible move to the Premier League this summer.

5 RILEY McGREE

(From Charlotte FC, Jan 2022, £3m)

Over the last couple of seasons, McGree has spent as much time out of the Boro team as in it, with a succession of niggling injuries taking a heavy toll. However, that shouldn’t detract from the overall effectiveness of his time as a Boro player, which has seen the Australian more than repay the £3m that was spent to sign him. McGree has made exactly 100 Boro appearances, scoring 15 goals, with his energy, commitment and positional versatility earning him praise from both Wilder and Carrick.

4 AIDAN MORRIS

(From Columbus Crew, Jun 2024, £3.1m)

Morris was Boro’s first signing last summer, and at the time, the Teessiders were convinced they had secured themselves a bargain at a price of just over £3m. Twelve months on, and their initial assessment has been thoroughly justified. Morris had an excellent first season in English football, with his dogged defensive work at the heart of midfield combining with a calm assurance when in possession. The 23-year-old US international still has the potential to improve, which is an exciting prospect given that he is contracted to 2028.

3 RAV VAN DEN BERG

(From PEC Zwolle, Jul 2023, £4m)

Van den Berg had the choice of a host of different clubs when he decided to leave his native Netherlands two summers ago. AC Milan wanted him, but Boro convinced the teenager they were the right place for him to develop his career. The last two seasons have been win-win – van den Berg has played regular Championship football and improved as a player; Boro have benefited from the services of one of the best young defenders in Europe. Having starred at the recent Under-21 Euros, van den Berg is now attracting interest from across the continent again. If Boro sell, they’ll get an awful lot more than the £4m they spent two years ago.

2 MORGAN ROGERS

(From Man City, Jul 2023, £1.5m)

Buy a player for £1.5m in the summer, sell him for £15m the following February. By anyone’s standards, that’s a remarkable piece of transfer business. Rogers didn’t really look like a Champions League player in the making for most of his Boro career, but that was largely because injury issues forced Carrick to play him as a central striker rather than as an attacking midfielder. Once Rogers switched to the flank, he looked a completely different prospect, with Boro continuing to benefit from his subsequent progress at Villa Park. When he eventually leaves Villa, Boro’s sell-on earnings will be astronomical.

1 EMMANUEL LATTE LATH

(From Atalanta, Aug 2023, £4m)

Like with Rogers, Boro made a fortune from Latte Lath. Signed from Atalanta for an initial fee of £4m in the summer of 2023, the Ivorian was sold to Atalanta United for an eyewatering £22.5m this February. Unlike with Rogers, however,  Boro also saw the best of Latte Lath during his time on Teesside. Latte Lath scored 29 goals in just 67 appearances with Boro, the highlight of which was the remarkable run at the end of the 2023-24 season that saw him score 11 goals in 12 matches. Boro resisted an approach from Ipswich at the end of that campaign, but ultimately, money talked and he headed off to America. A successful deal all round.