Chelsea - and every other Premier League club - have finally been given the green light to delve into the European market. The summer transfer window officially opened on Monday, July 1 - just over two weeks after the Premier League unbolted their gates on Friday, June 14.

Enzo Maresca will no doubt look to further bolster his new squad in the coming weeks following the arrival of Tosin Adarabioyo, who joined the Blues from Fulham on a free. The Blues continue to be mooted with some big names but, for now, it remains unclear whether the war chest will be deployed.

If Chelsea want to break the bank again this year, they may be left with no choice but to offload a few players. Conor Gallagher and Trevoh Chalobah face particularly uncertain futures, with any potential sale going down as pure profit on the books.

For now, though, they both have contracts at Cobham. So, with that being said, football.london has taken a look at one player from each of Europe's top-four leagues that the west Londoners could sign.

Nico Williams - Athletic Bilbao, La Liga Williams has been heavily linked with a move to the Premier League recently as he continues to impress for Spain at Euro 2024. The 21-year-old winger has taken the tournament by storm, firing his country into the quarter-finals on Sunday night, but he also enjoyed a brilliant season in the Spanish top flight.

He featured 31 times in La Liga last season, scoring five goals and providing 14 assists. Playing a key role in Ernesto Valverde's side, Williams helped Athletic Bilbao finish fifth in the Spanish top flight and secure Europa League qualification.

The PS49m-rated winger also led Los Leones to Copa del Rey glory, ending a run of six successive final defeats in the competition and a 40-year trophy drought. Williams sees his contract at the San Mames Stadium expire in June 2027.

Last month, he was quizzed on his future by Spanish radio station RNE. Williams said: " It's hard to deal with, because everyone is constantly asking you what you're going to do with your future.

"I'm a 21-year-old kid who just wants to play football. I have already said that Athletic is my home. I only recently renewed [my contract]. I am very happy.

"[Inaki] has already experienced it. He had his moment many years ago with rumours from the outside. He knows what it's like, he knows how you suffer and he knows what has to be done."

Joshua Kimmich - Bayern Munich, Bundesliga Kimmich faces an increasingly uncertain future at Bayern Munich, with his contract at the Allianz Arena set to expire in 12 months. The 29-year-old midfielder could be available for a cut-price fee this summer as the German giants weigh up whether they should cash in before it's too late and or allow his to leave on a free next year.

He featured 28 times for Bayern Munich in the Bundesliga last season, providing seven assists from holding midfield and right-back. While Kimmich couldn't lead the Bavarians to glory, he did help the club reach the Champions League semi-final where they were stopped by the to-be winners, Real Madrid.

The PS42m-rated maestro will be hoping to finally get his hands on some silverware this summer. Kimmich has played a key role for Germany at Euro 2024 so far, booking Julian Nagelsmann's side a place in the quarter-finals against Spain on Friday night.

In April, Kimmich insisted that he remains focused on his future at Bayern Munich. Speaking to Spanish outlet AS, the German said: "I want to talk to Bayern. And when I do that, I won't go out and talk to the press about it. I'm only focused on the two games against Real Madrid."

Theo Hernandez - AC Milan, Serie A Hernandez, who sees his contract at the San Siro expire in June 2026, emerged as a shock target for Chelsea late last month. The 26-year-old defender has been briefly linked with a move to the Premier League on numerous occasions as he continues to impress for AC Milan in the Serie A.

He featured 32 times in the Italian top flight last season, scoring five goals and providing four assists from left-back. Despite some underwhelming results, the France international earned a place in Didier Deschamps' starting lineup at Euro 2024.

According to HITC, higher-ups at Stamford Bridge believe Hernandez would be an 'ideal fit' for Enzo Maresca and his system. Speaking to reporters in June, the PS51m-rated left-back refused to commit his future to the Rossoneri.

"Whether I will stay at Milan or leave, we will see later," said Hernandez. "We'll see later whether I stay or not. At the moment I'm only focused on the European Championship."

Jonathan David - Lille, Ligue 1 Towards the end of last month, football.london understands that Chelsea started talks with David's representatives over a possible move to Stamford Bridge this summer. It's believed that the 24-year-old striker is eager to leave Lille after four years at the club.

The Blues are in the market for another centre-forward to provide competition and support for Nicolas Jackson, who was the only natural frontman for large parts of last season. football.london understands that there are several names on Chelsea's radar, and David is now being strongly considered.

Talks have taken place with the PS42m-rated Canadian's entourage to see if he would be interested in moving to west London. However, nothing has been decided yet as Maresca explores his options ahead of pre-season.

In June, the Lille president revealed that the club are open to selling David this summer. Olivier Letang said: "We have two players who have an exit voucher with Leny [Yoro] and Jonathan [David]."

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