Chelsea will renew their interest in Jules Kounde if they are unable to persuade Antonio Rudiger to sign a new deal, according to reports.
Both clubs will be free to hold talks with Rudiger from January 1 onwards, and the central defender could even sign a pre-contract agreement with one of them.
Negotiations have proved difficult, though, and the European champions are therefore beginning to look at potential replacements.
According to the Daily Mirror, Chelsea are ready to go back in for Kounde if Rudiger does not put pen to paper on fresh terms.
The Blues tried to sign the Frenchman in the summer but were unable to prise him away from Sevilla.
Thomas Tuchel's side stepped up their interest in the 22-year-old towards the end of the window.
They believed an offer of £42.8m would be enough to strike a deal, but Sevilla raised their asking price late on.
Chelsea were told they would need to trigger Kounde's release clause of £68m, but the Spanish side could lower their demands next summer.
Tuchel will certainly hope that is the case as he seeks to bolster his defensive options.
In the meantime the west Londoners are keen to tie Andreas Christensen down to a new deal as soon as possible.
The Denmark international is also out of contract next summer, but Chelsea are confident that he will remain at Stamford Bridge beyond the 2021/22 campaign.
But with Rudiger inching towards the exit door and Thiago Silva now 37 years old, there is a need for the Blues to strengthen in the centre-back department.
Reports suggest Kounde would be keen on a move, but Chelsea must first agree a deal with his employers.
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