Manchester City are reportedly keeping tabs on Antonio Rudiger's contract situation at Chelsea.
The 28-year-old will see his current deal at Stamford Bridge expire in June and he is now free to sign pre-contract agreements with foreign clubs.
According to journalist Gianluca Di Marzio, via the Manchester Evening News, Man City are monitoring the German defender ahead of a potential approach to sign him as a free agent.
The report adds that Barcelona, Real Madrid and Tottenham Hotspur are also keeping tabs on the Blues centre-back.
Should Rudiger decide against extending his contract at Stamford Bridge, then a switch to the Santiago Bernabeu is believed to be his preference.
Rudiger, who has been an integral figure in Thomas Tuchel's side this season, scored the only goal in Chelsea's 1-0 win away at Spurs in their EFL Cup semi-final second leg on Wednesday night.