Manchester United have reportedly joined the list of interested parties keeping tabs on Antonio Rudiger's situation at Chelsea.
The 28-year-old is close to entering the final six months of his contract at Stamford Bridge, with his current deal due to expire at the end of this season.
Rudiger will be able to open talks with foreign clubs over a free transfer from January 1, with Real Madrid thought to be the front-runners in the race for his signature.
Los Blancos have reportedly already held talks with the centre-back, although no decision has yet been made on his future and Chelsea remain keen to keep him.
The likes of Paris Saint-Germain, Bayern Munich, Manchester City, Liverpool and Tottenham Hotspur have all previously been credited with an interest in his signature, and Sky Deutschland claims that Man United have now also thrown their hat in the ring.
The Red Devils have shipped 24 goals in 16 Premier League games this season - more than any other team in the top seven - while summer arrival Raphael Varane has struggled with injuries at times so far in 2021-22.
Should Rudiger leave Stamford Bridge on a free transfer then reports have suggested that he could become one of the best-paid defenders in world football on a wage of around £400,000 - more than four times what he currently earns at Chelsea.
The Germany international remains a key part of Thomas Tuchel's first-team plans for the European champions, making 21 appearances across all competitions.