[Callum O'Connell
Callum O'Connell](https://www.footballinsider247.com/author/callum-o-connell)
The 33-year-old is out of contract at the end of the season, and reports in Spain have suggested he is unlikely to put pen to paper on an extension under Jose Mourinho.
As a result, clubs across world football have been placed on high alert over the Germany international's availability, with the Blues now emerging as a surprise destination.
Former Man United chief scout Mick Brown told Football Insider that Xabi Alonso's side are in need of experienced heads and defensive depth, making Rudiger a key target.
The move has been likened the Chelsea's signing of at-the-time 36-year-old Thiago Silva, who moved to Stamford Bridge in 2020 and established himself as a crucial asset.
Rudiger could play a similar role in this Chelsea team, which is in need of leadership and defensive options, and would provide a significant boost to Alonso's side on and off the pitch.
Could Chelsea make a move to sign Antonio Rudiger?
Football Insider revealed on 14 October that Rudiger could finally return to the Premier League despite opting to remain at Real Madrid during the summer transfer window.
A return to Stamford Bridge, where he spent five years between 2017 and 2022, could appeal to the defender while there is a feeling he would be welcome back at Chelsea.
"Antonio Rudiger is certainly going to be one to watch if he has decided to leave Real Madrid," Brown told Football Insider.
"I'm sure there will be a lot of interest from clubs in the Premier League, and it wouldn't surprise me actually if Chelsea decided to make a move and bring him back.
"They are in need of a new centre-back and they want to add some experience to the side, so it would make a lot of sense to target Rudiger on a free transfer.
"It's something I think would make a lot of sense, plus he's well-liked by the supporters and knows the club, so he could be the ideal target for them.
Why do Chelsea want a new centre-back?
Rudiger is not the only centre-back to be linked with a move to Chelsea after what has been a mixed start to the season, especially defensively, at Stamford Bridge.
The Blues have conceded 15 goals in eight Premier League games so far, more than any other side in the top half, and the joint-third most in the league overall.
Former Tottenham scout Bryan King told Football Insider last month that Alonso must address his side's defensive woes, with the addition of new options highly likely.
Levi Colwill, Maxence Lacroix and Josh Acheampong started in the back three against Tottenham last time out, leaving Wesley Fofana as the only option from the bench.
That lack of depth has been flagged as a significant concern, and with Rudiger likely to become available on a free, he could be the ideal target to address those issues.