Chelsea defender Antonio Rudiger may not be at Stamford Bridge next season. The German’s current contract with the Blues runs out at the end of the 2021-22 campaign and he is yet to sign an extension.Rudiger has been serving the west London outfit diligently since his arrival from Roma in 2017. The German international has helped the club to the Champions League, the Europa League and the FA Cup amongst other honors and remains a regular under Thomas Tuchel. Chelsea are eager to keep the 28-year-old in London, but have seen a couple of their offers shot down.The likes of Real Madrid and Paris Saint-Germain are reportedly interested in the player and are offering lucrative packages to sway the player in their direction. If they or any other European heavyweight is successful in signing the centre-back as a free agent, the reigning European champions will need a replacement.Today, we will take a quick look at five players who could fill in for Rudiger if he decides to leave for greener pastures:#5 Pau Torres – VillarrealJapan v Spain - U-24 International FriendlyLa Liga star Pau Torres has made quite a name for himself over the last couple of seasons. The Spaniard has consistently performed for Villarreal and is drawing attention from some of the biggest clubs in Europe as a result.Premier League giants Chelsea are reportedly keeping a close eye on Torres and could make a move for him if Rudiger does not renew.ً@jdp433Pau Torres - Passing Ability11:28 AM · Feb 7, 202221036Pau Torres - Passing Ability https://t.co/u5RwXA5M9zTorres, a left-footed centre-back, is calm and collected on the ball and can carry it effortlessly if needed. He can also deliver pinpoint long balls from deep and is known to catch the opposition out with his deliveries.Barcelona are also believed to be interested in the Spaniard’s services, meaning Chelsea could have to spend quite a bit to get him.#4 Eder Militao – Real MadridFC Barcelona v Real Madrid CF - LaLiga SantanderSince his move from Porto in 2019, Eder Militao has been a star performer for Real Madrid. Following the departures of Sergio Ramos and Raphael Varane last summer, the Brazilian has come on his own and has been leading the side by example.Tuchel’s Chelsea have reportedly been left impressed by the player and want to bring him to Stamford Bridge if Rudiger departs.Absolute Chelsea@AbsoluteChelseaReal Madrid's Eder Militao is 'in #Chelsea's future plans' and 'on the radar' of Thomas Tuchel.[@diarioas via @Sport_Witness]4:00 AM · Feb 7, 2022197693Real Madrid's Eder Militao is 'in #Chelsea's future plans' and 'on the radar' of Thomas Tuchel.[@diarioas via @Sport_Witness]The Londoners allegedly offered Real Madrid £34million for Militao ahead of the winter transfer window, but Los Blancos turned them down.If Madrid’s stance change next summer, possibly with a big offer from Chelsea, we could very well see the 24-year-old at the Bridge next summer.