Cesar Azpilicueta has triggered a one-year extension of his deal at Chelsea after playing a certain number of games this season according to The Athletic.
The Spaniard's contract was going to expire in the summer and Barcelona have been in talks over signing him on a free transfer.
The 32-year-old has activated a performance-related clause inserted by Chelsea in his previous contract signed in 2018.
The Blues are currently prohibited from agreeing new deals with players due to sanctions on owner Roman Abramovich, but Azpilicueta's extension clause was pre-agreed and automatically triggered after a specific number of appearances.
It is understood the 32-year-old is yet to make a decision on his future and awaits news regarding the club's ongoing takeover process.
Meanwhile, Barcelona have held talks with Rudiger and president Joan Laporta has suggested a deal with Christensen is already agreed, with both Chelsea defenders out of contract in June.
Azpilicueta's arrival in 2012 from Marseille in a deal worth £7million has proven to be one of the best pieces of business the club have done in recent years.
Azpilicueta – affectionately known as 'Dave' to many Blues fans – has made 464 appearances and counting for the Blues, scoring 16 goals and providing 56 assists.