Chelsea manager Thomas Tuchel is sweating over the fitness of defender Andreas Christensen after he was withdrawn from the Lille game in the first half due to injury.
The Blues progressed in the Champions League midweek thanks to the aggregate win over the French outfit, but the result was soured slightly by the injury collected by Christensen.
Even if the injury is not as bad as once feared, it is unlikely the Dane will be risked for the FA Cup tie against Middlesbrough on Saturday evening.
Tuchel has also had to contend with fitness issues for both Reece James and Callum Hudson-Odoi recently, as the pair didn't even travel to Lille for European duties.
The German has already said they will be assessed closer to kick-off on Saturday, but like with Christensen, it is unlikely they will be risked.
Saul Niguez has tested positive for Covid and will miss out.
Kepa Arrizabalaga will replace Edouard Mendy in goal as he remains the club's domestic cup keeper even after his missed penalty cost Chelsea the League Cup.
Trevoh Chalobah will come into the back three alongside Thiago Silva and Antonio Rudiger.
Cesar Azpilicueta and Marcos Alonso will continue in their respective wing-back.
Mateo Kovacic may drop out of the starting XI to be replaced by Mason Mount, with Jorginho and N'Golo Kante retaining their spots.
Romelu Lukaku and Timo Werner could be given the opportunity to impress, with Christian Pulisic and Kai Havertz dropping to the bench.