Arsenal gamble on Christos Tzolis while Barcelona strike smart deal for Karim Adeyemi: GOAL grades the biggest transfers of summer 2026

The summer transfer window continues to gather momentum as Europe’s biggest clubs reshape their squads ahead of the new season.

Arsenal have strengthened their attack with the arrival of Christos Tzolis, Aston Villa have gambled on Alejandro Garnacho, while Barcelona believe Karim Adeyemi could finally fulfil his enormous potential at Camp Nou.

Here are GOAL’s latest transfer grades.

Christos Tzolis (Club Brugge to Arsenal – £34m)

For Club Brugge: A

Club Brugge have secured a club-record transfer fee for a player they signed for just €6.5 million two years ago. Negotiations remained straightforward, Arsenal met the Belgian champions’ valuation, and the sizeable profit provides Brugge with significant resources to strengthen their squad following another league title.

For Arsenal: B+

The Premier League champions needed greater depth on the wings after Leandro Trossard’s departure, and Tzolis arrives following a sensational campaign that produced 22 goals and 29 assists.

The biggest concern remains his disappointing spell at Norwich City, where he struggled to adapt to Premier League football. However, he returns older, physically stronger and considerably more experienced. Arsenal are betting that his development in Belgium has prepared him for a second chance in England.

For Tzolis: A+

Returning to the Premier League offers Tzolis the perfect opportunity to rewrite the narrative surrounding his time at Norwich.

Having rebuilt his reputation through impressive spells at Fortuna Dusseldorf and Club Brugge, the Greece international now joins the league champions after reportedly prioritising Arsenal over every other suitor.

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Alejandro Garnacho (Chelsea to Aston Villa – Loan with conditional obligation)

For Chelsea: A

Chelsea deserve credit for moving Garnacho on quickly after an underwhelming campaign at Stamford Bridge.

The loan includes a conditional obligation to buy that is reportedly straightforward to activate, allowing the Blues to recover most of their investment while creating room for further squad changes.

For Aston Villa: C

Villa are taking a considerable gamble.

Unai Emery believes he can revive Garnacho’s career, but the Argentine’s performances over the last 12 months hardly justify the likely transfer fee attached to the agreement.

Replacing Morgan Rogers will be a major challenge, and Garnacho must quickly rediscover the confidence and explosiveness that once made him one of England’s brightest young talents.

For Garnacho: B

Another fresh start presents Garnacho with perhaps his final opportunity to fulfil his enormous potential.

Emery has revitalised struggling players before, but he has also shown little hesitation in freezing out those who fail to meet his demanding standards. Competition for places remains fierce, meaning Garnacho will have to earn every minute.

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Karim Adeyemi (Borussia Dortmund to Barcelona – €29m)

For Borussia Dortmund: B

With only one year remaining on Adeyemi’s contract, Dortmund had little choice but to sell.

Although the transfer fee falls below the player’s true market value, the Bundesliga side avoided losing him for nothing next summer while also negotiating a valuable sell-on clause.

For Barcelona: B+

Barcelona may have quietly completed one of the smartest deals of the summer.

Adeyemi arrives younger, cheaper and quicker than several alternative targets, while Hansi Flick already knows the Germany international well after handing him his senior debut.

If Flick can unlock Adeyemi’s consistency, Barcelona may have secured outstanding value.

For Adeyemi: A

The move feels perfectly timed.

Adeyemi’s Dortmund career promised much but rarely delivered consistently, yet at just 24 years old, his ceiling remains extremely high.

The relatively modest transfer fee also reduces external pressure, allowing him to develop without immediately carrying the weight of being Barcelona’s marquee signing.

Final verdict

Among the latest blockbuster deals, Barcelona’s signing of Karim Adeyemi appears the smartest piece of business, combining relatively low financial risk with enormous upside.

Arsenal’s move for Christos Tzolis is more of a calculated gamble, banking on the Greek winger’s remarkable improvement since his difficult Norwich spell.

Meanwhile, Aston Villa face the greatest uncertainty, with Alejandro Garnacho still searching for the form that once made him one of Europe’s most exciting young prospects.