Rudiger joined Chelsea in 2017 from AS Roma, where he won the FA Cup, Champions League, Europa League, UEFA Super Cup, and Club World Cup.
Chelsea confirmed last week that terms have been agreed with a consortium led by Los Angeles Dodgers part-owner Todd Boehly and backed by Clearlake Capital over the 4.25 billion pounds ($5.24 billion) acquisition of the London club.
The proposal has been sent to the government and Premier League for approval.
Last month, Chelsea boss Thomas Tuchel announced that the 29-year-old German would be leaving the club.
Sanctions imposed by the British government on Chelsea owner Roman Abramovich following Russia`s invasion of Ukraine means the club cannot hand out contracts or buy new players.