Heading into this summer, none of Chelsea's centre-backs - Antonio Rüdiger, Fikayo Tomori, Andreas Christensen and Kurt Zouma - felt as though they were safe. Frank Lampard wanted a new signing and had failed to commit to any of the quartet in the previous year.
When big wages were handed out to Thiago Silva, it became clearer that one of the group would be shipped out, and up until now, the casualty looked set to be Tomori, who was wanted on loan by both Everton and Rennes.
Chelsea have delayed pulling the trigger on Tomori's exit for a while, and now it's clear why. The man who could be discarded could be Rüdiger.
The German was omitted from Chelsea's matchday squad to face Liverpool on Sunday, despite not carrying an injury. According to The Telegraph, Rüdiger is set to meet with his agent in the coming days to discuss his options.
With just two years remaining on his contract, it's time to let Rüdiger go.
On paper, Rüdiger is probably Chelsea's best centre-back. On his day, he's an outstanding defender with a brilliant passing range. He's everything you could possibly want in a centre-back, but the problem is that side of him doesn't come out often enough.
Inconsistency is Rüdiger's problem. You will see the German make a bizarre decision or fail to deal with a routine threat far too often - ducking away from headers and giving opponents a free shot at Kepa Arrizabalaga became his trademark last year - and that's obviously not what you want when you're trying to challenge for major honours. It costs points, just like it did against Newcastle United in January.
However, make no mistake about it, Tomori is far from perfect as well. The Englishman has flashed glimpses of greatness and combined them with a number of poor performances which saw him dropped from the squad for the majority of the second half of last season, and deservedly so.
The difference is that Rüdiger is 27 and will soon see his value drop (especially if he's not playing games), whereas Tomori is 22 and projects to become a core part of the squad in the future.
Rüdiger is now at a point in his Chelsea career where a decision needs to be made. Does he get a lucrative contract renewal, or do the Blues sell now before his price starts to drop?
He's probably Chelsea's most valuable centre-back right now, and the Blues' hierarchy will recognise that. Not cashing in this summer would be a waste - especially when Chelsea need to sell to cover their hectic spending spree.
With Rüdiger gone, Tomori would get more opportunities to play alongside Silva, Zouma and Christensen, which would only make him better and would allow him to eventually replace Silva when the Brazilian moves on.
Not only will it allow Tomori to grow, but Chelsea would have the money to pursue a new centre-back next summer. With an £80m move for Declan Rice being touted in the media, the Blues need every penny they can get.
Rüdiger has had his great moments in Chelsea blue and his role as Agent Rüdiger in the recruitment of Timo Werner and Kai Havertz won't be forgotten anytime soon, but Lampard cannot afford to be sentimental.
Tomori is the future of Chelsea's defence, not Rüdiger. Chelsea must cash in on the German and give Tomori the chance to grow in his place.