Chelsea boss Mauricio Pochettino admits Christopher Nkunku as suffered an injury setback.
The striker missed Saturday's FA Cup win against Preston.
Pochettino said: "It's really tough. The circumstances are really tough from the beginning of the season. Broja, Nkunku, Lavia, sometimes it is difficult to explain for the fans.
"Like Nkunku, we don't want to put pressure on him, because we know after a long time injured always it is difficult to come back and start to perform. After six months away from the competition it is always tough.
"Now he wasn't involved because he suffered some problem in his hip after training yesterday and now we need to check and see if it will be possible for him to be ready for the next few games.
"That is the problem, they need game time to get their best and sometimes we cannot provide this game time to players who need to feel the competition, because in the end we are Chelsea, we need to win.
"Sometimes it is really tough to explain that to players who feel the pressure to play and perform because they want to help the team."