Exclusive - Chelsea's 2021/22 season may be going according to plan on the pitch, but 90min understands the club are facing up to the prospect of losing three key defenders ahead of next season - unless they can persuade Andreas Christensen and Antonio Rudiger, as well as captain Cesar Azpilicueta, to sign new contracts.
Christensen, who has just eight months remaining on his current deal, has been unable to agree a new contract at Stamford Bridge, following a standout 12 months that's seen his reputation and standing in the game considerably improve.
It's a similar situation for Rudiger who 90min confirmed in September was nowhere near agreeing a new deal at Chelsea, and to even consider staying he wanted to become one of their highest paid players.
That stance has not wavered and Chelsea are now faced with an even bigger problem - Rudiger is wanted by virtually every major club in Europe.
Paris Saint Germain, Bayern Munich and Tottenham were already circling - making it clear they would be prepared to make him one of the highest paid defenders in the world - but there is also strong interest from Premier League champions Manchester City; a club more than capable of paying enormously high wages.
If those four options weren't enough for Rudiger, he also has Real Madrid, Barcelona, Atletico Madrid and Juventus ready to make him an offer, while there's also genuine interest from Liverpool and Manchester United.
Rudiger can officially listen to offers from 1 January, and it's understood that Chelsea’s hierarchy have accepted that the 28-year-old is now ‘more than likely’ to leave at the end of the season.
Head coach Thomas Tuchel had previously insisted that committing Rudiger to a new contract should be one of Chelsea's top priorities, but it appears the German is struggling to get his way.
Tuchel's agitation will only increase with the news that Christensen has so far failed to agree terms on a new contract. The 25-year-old enjoyed a brilliant European Championship with Denmark and has been in excellent form for the best part of a year - keeping 42 clean sheets in his last 52 appearances for club and country.
Like Rudiger, he is out of contract next summer, and although the Dane is not demanding as much money as his teammate - Rudger is looking for a contract worth in excess of £300,000-a-week - he is looking for a substantial pay rise that reflects his continued fine form.
As it stands, Chelsea aren't prepared to meet his demands, to such an extent that talks have come to a halt. That leaves the club just two months to re-engage in talks and agree a financial package, or they run the risk of Christensen negotiating a transfer in January to a club willing to stump up the cash.
To make matters worse, Chelsea - who also let Kurt Zouma join West Ham in the summer - are yet to tie down captain Cesar Azpilicueta to a new contract, although they are confident that he's committed to the club and is keen to stay.
Atletico Madrid are leading the chase for Azpilicueta, should he be available, as they see him as an ideal replacement for England international Kieran Trippier – who is likely to leave Spain at the end of the season.