LIVE Transfer Talk: Barcelona, Atletico Madrid vying for Chelsea's Cesar Azpilicueta

The summer transfer window was unlike any other. See all the major deals and check out how we graded the biggest signings. And just because the window is shut until January, that doesn't mean the rumours won't keep coming. Here's the latest gossip and speculation.

TOP STORY: Barca, Atleti to battle for Azpilicueta

Barcelona and Atletico Madrid are interested in Chelsea captain Cesar Azpilicueta on a free transfer, says Sport.

The Spain international is one of a number of Blues defenders out of contract at Stamford Bridge in the summer, meaning he is able to discuss a deal with foreign clubs as of Jan. 1.

The 32-year-old has spent nearly 10 years at Chelsea, joining from Marseille in 2012 and making 446 appearances for the club in that time.

Sources told ESPN in November that Barcelona were following the versatile defender, with new boss Xavi Hernandez hoping to add experience and leadership to his young squad.

Along with Azpilicueta, there's also Antonio Rudiger, Andreas Christensen and Thiago Silva who have contracts that expire in the summer, leaving Thomas Tuchel with a potential centre-back shortage on his hands going into next season.

Rudiger has been heavily linked with a move to Real Madrid in recent months, with the Blues beginning talks over a new contract but yet to get the Germany star to commit to staying in London.

Barca have also been linked heavily with Christensen, who Chelsea are believed to have had talks with over a new deal, but they have stalled with the Denmark international being dropped for a game.

As for Silva, it is believed he will sign for another year at Stamford Bridge, impressing since his free transfer from Paris Saint-Germain.

Time will tell if Tuchel is left with a shortage at the back, however it could force his hand to go into the transfer market to shore up his defensive options.

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LIVE BLOG

21.33 GMT: Ekrem Konur writes that Loris Karius wants to terminate his contract with Liverpool. The 28-year-old goalkeeper has found himself out of favour under Jurgen Klopp since the arrival of Alisson, and despite some loan moves throughout Europe, he has been unable to break in to the first team. He has previously been linked with Bundesliga side Greuther Furth.

20.57 GMT: Foot Mercato reports that a number of clubs in France are tracking midfielder Corentin Tolisso with interest in a potential loan deal. The 27-year-old has been the subject of interest from a number of clubs across Europe, but with his contract set to expire this summer, Bayern Munich may only be prepared to move him on a permanent deal as they prepare to be active in the January transfer market.

20.20 GMT: Fenerbahce are considering a move for Barcelona forward Luuk de Jong in January, reports Mundo Deportivo. The 31-year-old Netherlands international is reported to be aware that the Catalan club are looking to move him on after scoring just one goal in 11 appearances, and he could revive his career in Turkey as early as January as Blaugrana boss Xavi Hernandez expects to be without him for the second half of the season.

19.42 GMT: Juventus have made contact with Everton registering their interest in left-back Lucas Digne, according to Calciomercato. The Serie A club view the 28-year-old as a potential replacement for Alex Sandro, whose recent performances have seen the club's hierarchy begin to look for alternatives, but the France international has a contract at Goodison Park that runs until 2025.

19.03 GMT: Andre Onana will sign with Internazionale despite late interest from Barcelona over a free transfer.

Fabrizio Romano writes that the 25-year-old goalkeeper appreciates the interest from his former club, but still intends to commit his future to the San Siro side next summer. Onana returned to action for Ajax Amsterdam in November, following a lengthy and controversial doping ban, but has been linked with an exit throughout the final year of his contract.

18.23 GMT: Bayern Munich are prioritising getting Niklas Sule to sign a new contract before advancing talks in the chase for Chelsea stalwart Antonio Rudiger, according to BILD. It is reported that the Bundesliga club are still one of many sides interested in the 28-year-old centre-back, despite rumours suggesting that they were dissuaded by high salary demands.

17.42 GMT: Sport Italia reports that Newcastle United are preparing a bid for 21-year-old centre-back Sven Botman in the January transfer window. It is reported that Lille will only consider offers in the region of €30m for the Netherlands youth international, who has been attracting interest from the Premier League since the summer.

17.00 GMT: Done deal! Corinthians have confirmed the signing of Paulinho on a free transfer. The 33-year-old was out of contract after last playing for Al Ahli in Saudi Arabia, and despite some offers from around Europe, the former Tottenham Hotspur midfielder has decided to head back to his home of Brazil.

16.17 GMT: Chelsea midfielder Conor Gallagher will not be recalled early from his season-long loan at Crystal Palace because of a clause inserted into the deal, The Times reports.

Gallagher, 21, has scored six goals and set up another three in the Premier League so far this season, and earned him a first senior England cap during the last international break. Following on from his eye-catching loan spell at West Bromwich Albion last season, Gallagher is establishing himself as one of the most promising young players in England, leading to speculation that he could be welcomed back into the fold at Stamford Bridge next season or even be recalled in January.

However, the terms of Gallagher's loan to Selhurst Park mean that he could only be recalled in January if he had played fewer than half of Palace's matches up to that point. He has missed just one game for them so far this season.

15.29 GMT: The Sun reports that West Ham United are one of the European clubs interested in signing New York City FC striker Valentin Castellanos.

Castellanos, 23, finished the regular season with 19 goals before adding three in the play-offs as New York City claimed the first MLS Cup triumph in their history after defeating the Portland Timbers in a penalty shootout.

NYCFC have the same owners as Premier League champions Manchester City, whose manager Pep Guardiola revealed he has had conversations with the City Football Group's scouting department about his future.

"I think he is a guy who will do the next step in Europe," Guardiola told a news conference. "What I saw when the scouting department talked to me, I know he's a quality player and ready to make the next step to Europe and we will see where."

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14.41 GMT: The January transfer window is getting ever closer and clubs are starting to think seriously about the players they want to strengthen their squads.

Traditionally, midseason isn't a time for major moves, but the COVID-19 pandemic's impact on football finances is unpredictable and the summer window saw plenty of spending in spite of the situation.

Here, ESPN's Tor-Kristian Karlsen breaks down some of the players on the radar for some of Europe's biggest clubs.

- Karlsen: Vlahovic, Mbappe among top January transfer targets

13.47 GMT: Atletico Madrid president Enrique Cerezo has described forward Joao Felix as "untransferable" after reports linked the Portugal international with a move in January.

Both the newspaper Diario AS and radio station Cadena SER reported earlier this month that agent Jorge Mendes had told Atletico that he would push to force a departure in the upcoming window.

Joao Felix, 22, has struggled to adapt to Diego Simeone's team since arriving from Benfica in a €126m deal in 2019.

"He's a magnificent player," Cerezo told El Larguero on Tuesday. "He has a long contract. For us he's untransferable. We took a chance on him."

12.54 GMT: Real Betis midfielder Sergio Canales has signed a new contract through 2026 with a release clause rising to a €1 billion, a new club record.

Canales' previous deal was due to expire in June 2023. Since joining Betis in 2018, the former Valencia and Real Madrid player has scored 27 goals and set up 20 more in 138 official games.

Canales, 30, said after putting pen to paper when asked if he plans to retire at Betis: "Football has taught me that you have to take it one step at a time. I would love to stay here for thousands of years. They are helping me to grow as a footballer and as a person and I want that to continue."

12.02 GMT: Tottenham Hotspur are prepared to listen to offers for Dele Alli in January, sources have told ESPN's James Olley.

Spurs boss Antonio Conte has indicated that the 25-year-old is not a key part of his plans for the second half of the season, sources had told ESPN, with Conte willing to allow him to revive his career elsewhere.

Significantly, chairman Daniel Levy is also ready to soften his stance having blocked multiple attempts from Paris Saint-Germain to take the midfielder on loan last summer.

Sources have told ESPN that Alli was open to joining the Ligue 1 side, with the prospect of being reunited with former Tottenham head coach Mauricio Pochettino at the Parc des Princes an appeal.

It is unclear at this stage whether PSG will revive their interest but Alli is desperate to change his fortunes after becoming a peripheral figure at Spurs, making just 14 appearances all season.

11.27 GMT: Barcelona striker Sergio Aguero has announced his retirement from football at the age of 33 due to a heart condition.

Aguero has not played since the end of October when he was taken off during the first half of Barca's draw with Alaves after experiencing chest pain.

Barcelona later announced that the discomfort had been caused by an arrhythmia -- a broad term to describe any heart rhythm that is not completely normal -- which would require treatment over a three-month period.

The former Manchester City forward has since been subjected to regular cardiac exams to monitor his health, with the results advising him it would be a risk to carry on with his professional career.

He announced his retirement at a news conference on Wednesday, joined by Barca president Joan Laporta.

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