No Chelsea fan wants to see Antonio Rudiger leave, but with his contract ending by the end of the season - and negotiations for an extension at an impasse - the only realistic resolution might be searching for the center-back's replacement.According to reports, Chelsea remain keen on extending Rudiger's contract, but his wage expectations (£140,000 a week) have stalled any potential breakthrough.Fabrizio Romano@FabrizioRomanoChelsea are still negotiating with Toni Rüdiger agents over new contract. Talks ongoing - there’s currently no agreement on salary but it’s not over as Rüdiger is so happy with Chelsea and Tuchel. 🔵🇩🇪 #CFCFC Bayern and Real Madrid are interested in case he’ll be a free agent.1:30 AM · Sep 30, 2021170581040Chelsea are still negotiating with Toni Rüdiger agents over new contract. Talks ongoing - there’s currently no agreement on salary but it’s not over as Rüdiger is so happy with Chelsea and Tuchel. 🔵🇩🇪 #CFCFC Bayern and Real Madrid are interested in case he’ll be a free agent. https://t.co/Gd6r8JidscWith the January transfer window just around the corner, clubs like Real Madrid and Paris Saint-Germain are watching with keen interest. Bayern Munich have shown more open interest in Rudiger, especially with manager Julian Nagelsmann stating, "I'll have to see when the contract expires, and then I'll see if I still have money in my wallet."The Sun Football ⚽@TheSunFootballAntonio Rudiger has reportedly been contacted by Bayern Munich, as Chelsea try to get him to sign a new contract10:52 AM · Sep 24, 2021526Antonio Rudiger has reportedly been contacted by Bayern Munich, as Chelsea try to get him to sign a new contract https://t.co/BpK4VeFAl3The 28-year-old German international already has several suitors who will agree to his wage demands, but so far, he has kept all his cards close to his chest. Stating that this was the most important decision of his professional career, Rudiger has explained that he won't be rushing into anything. While he might end up renewing his stay at Stamford Bridge, Chelsea have to make a decision in the event that he doesn't.To that end, let's take a look at five quality center-backs who could ultimately replace Antonio Rudiger at Chelsea.#5 Marquinhos | Paris Saint-GermainRB Leipzig v Paris Saint-Germain F.C - UEFA Champions League Semi FinalDuring Thomas Tuchel's two years at the helm of Paris Saint-Germain, he worked with the defensive partnership of Marquinhos and Thiago Silva. While the Parisian giants are unlikely to let Marquinhos leave, it won't stop Chelsea from trying to reunite the PSG star with both his former center-half partner and his manager.Notably, the Parisian club reportedly snubbed an £86 million offer for Marquinhos from the Blues during the last transfer window. However, if the 27-year-old Brazilian international is interested in sealing a big-money move to the Premier League, Stamford Bridge could be his next destination.#4 Maxence Lacroix | WolfsburgPreußen Münster v VfL Wolfsburg - DFB Cup: First RoundAccording to reports, Thomas Tuchel had his sights set on swooping one of the most attractive prospects in European football: Maxence Lacroix. The pacey center-back was brilliant for Wolfsburg during his debut season, making 30 Bundesliga appearances and contributing directly to two goals. Lacroix, only 21 years old, would be the perfect long-term replacement for Rudiger, and Tuchel is reportedly a big fan of the youngster.Lacroix recently extended his contract with Wolfsburg, having made nine appearances this season, but that would hardly deter the Blues. If he continues to perform consistently in the Bundesliga, Chelsea may be hard-pressed to make a large bid to lure the youngster to Stamford Bridge.