Bayern Munich are the latest club to have registered an interest in Chelsea's Antonio Rudiger, Goal can confirm.
The Bundesliga champions join Paris Saint-Germain and Real Madrid in keeping tabs on the Germany international's contract situation at Stamford Bridge.
As previously reported by Goal, the European heavyweights are monitoring Rudiger's situation as he is yet to sign a contract extension with Chelsea and his current deal is set to run out next summer.
How concrete is Bayern's interest?
Bayern have been in touch with Rudiger's agent and brother, Sahr Senesie, but the talks are purely preliminary at this stage.
Julian Nagelsmann's side consider the 28-year-old to be a good replacement for Niklas Sule should the latter choose to move on from the Allianz Arena next summer.
Like Rudiger, Sule's contract expires at the end of the season, and he has put extension talks on hold as he has not yet decided whether he wants to continue with the Bundesliga champions.
There is, however, no hurry for both Sule and Bayern, while Nagelsmann has been pleased with the player's development and feels there is no need for an additional central defender to be brought in if he decides to stay.
“I'm generally not a big fan of talking about players who are under contract elsewhere, and besides, we're outside the transfer period,” Nagelsmann told a press conference when asked about Rudiger.
“I'm talking about him now as a football fan because he is a German senior international. He has made a super development. Thomas [Tuchel] has handled him extremely well - he was still on the sidelines at Chelsea a year ago and is now certainly one of their most decisive players.
“He has incredibly good aggression and is a very good defender. I haven't spoken to Brazzo (Hasan Salihamidzic) about it and if I did, I wouldn't tell you either! I just read that in the media as well. I'll have to see when the contract expires and then I'll see if I still have money in my wallet!”
What does Rudiger want to do?
Talks are under way between Chelsea and Rudiger regarding a contract extension, although the Blues are remaining cautious over his demands.
The player himself is happy to stay in London but is aware that, given his age, his next contract may well be his final big-money deal.
In addition, interest from Europe's elite and the fact that Tuchel considers the defender a key member of his squad put Rudiger in a strong negotiating position.
“The fact that I didn't renew my contract when I was sitting in the stands is surely only logical for everyone,” Rudiger said in an interview with SID.
“When I started playing regularly again, I wanted to wait and see how everything would develop here. As I had announced, after the long Champions League season and the European Championship, the first talks took place after I returned to training with Chelsea.
“So this is less than two months ago and for me this will be the most important decision of my professional career, so I won't rush into anything. Personally, I haven't spoken to any other club than Chelsea.”
The bigger picture
Should talks with Chelsea break down, Rudiger will of course not be short of options given the magnitude of the clubs monitoring his situation.
The Blues, meanwhile, retain a keen interest in Sevilla defender Jules Kounde, and could return with a bid for the 22-year-old Frenchman in the January transfer window.