Raheem Sterling is a doubt for Chelsea’s game at West Ham after picking up another injury.
The England international returned to action last week against Fulham, having recently been sidelined by a hamstring problem.
He has now suffered a knock in training and seems unlikely to feature in the derby at the London Stadium.
Boss Graham Potter explained: “Raheem has a little knock after a kick to his knee during training. He’s doubtful for tomorrow.”
Meanwhile, Denis Zakaria and Wesley Fofana have been training with the squad following their recent injuries and Mateo Kovacic appears to be close to a return.
Potter said: “The injured players are getting closer.
“Wesley and Denis are back with the team. Mateo is back in team training but it (Saturday’s match) is too soon for him. His return is good news as it will give us options.”