Tottenham are interested in signing defender Antonio Rudiger from Chelsea.
The Germany international has been considering his future at Stamford Bridge having fallen down the pecking order among centre-backs at the club.
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Following Chelsea's summer acquisition of Thiago Silva from Paris Saint-Germain, Rudiger hasn't featured in the opening three Premier League games of the season.
Frank Lampard has favoured the likes of Kurt Zouma, Andreas Christensen, Fikayo Tomori, along with Silva, but Chelsea have struggled defensively, allowing six goals in their opening three games.
It is thought the 27-year-old would consider a loan move away for more game-time ahead of the European Championships next summer, but Chelsea are unlikely to let any of their players join Premier League rivals on temporary deals.
Chelsea declined to comment when contacted by Sky Sports News but they rarely do business with Spurs. Carlo Cudicini was the last player to swap Stamford Bridge for north London in 2009.
Rudiger alleged he was racially abused during Chelsea's game at Tottenham last December. Both the Metropolitan Police and Tottenham found no evidence to support the allegation.
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Speaking on Monday ahead of Chelsea and Spurs' Carabao Cup fourth-round meeting, Lampard warned that no assumptions should be made over Rudiger's future.
"I wouldn't assume anything," Lampard said. "And I wouldn't assume Antonio or any players in the squad (are leaving)."
Spurs have turned their attention to Rudiger given the high valuation of another target, Inter Milan's Milan Skriniar.
Chief scout Steve Hitchen made an enquiry about Skriniar on a trip to Milan last week, according to Sky in Italy.
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Spurs are interested but there is a big gap between each club's valuation of the Slovakia international.
Rudiger, who has suffered significant knee and groin injuries since joining Chelsea from Roma in 2017, would appear to be fully fit, having played all 90 minutes in each of Germany's Nations League matches earlier this month.
Summer transfer window - key dates and times
The summer transfer window closes at 11pm on Monday October 5 with a feast of activity lined up on Transfer Deadline Day on Sky Sports News and across our Sky Sports platforms.
A domestic-only window for deals between the Premier League and EFL then runs from October 5 and closes on Friday October 16 at 5pm. Follow all the news and analysis on SSN and across Sky Sports' digital platforms, including with our dedicated Transfer Centre blog.