Chelsea could be facing a crisis up front after Diego Costa pulled up in training with further hamstring problems, according to The Telegraph.
Jose Mourinho fears the top goalscorer could be out of action for up to three weeks, leaving Loic Remy as the only fit striker for next week's crunch clash against Manchester United.
Didier Drogba has been suffering with an ankle injury for the majority of the season and has yet to start a Premier League fixture or score a goal. Remy will lead the line for the Blues against Crystal Palace, but should the Frenchman suffer an injury, they will face Louis van Gaal's team with no recognised strikers.
Mourinho has stated his concern for Costa's hamstring injury time and again this season but has still opted to start him in every Premier League match. Having scored nine goals in his opening seven games, Costa looked anything but injured. However, it appears his issues have finally caught up with him.
Chelsea medical staff are managing Costa's injury with the aim of getting him fit as quickly as possible, but there are fears from within the club that the Spain international will require a three-week recuperation period.
Mourinho did not say whether or not Costa returned from international duty with the problem but the 26-year-old is believed to have pulled up in Chelsea training earlier this week.
It is the latest hamstring problem for Costa, who has struggled with the affliction since the end of last season with Atletico Madrid. It comes after Mourinho called for Vicente del Bosque to leave him out of his international squad for the Euro 2016 qualifiers against Slovakia and Luxembourg.
Costa played 172 minutes in total for Spain last week where he finally opened his international account with a goal in the 4-0 over Luxembourg.
While Mourinho will undoubtedly be annoyed, Costa himself claimed he was fit to play for Spain.
In an interview with El Comercio the feared forward explained: "I don't want to be in the middle (of Spain and Chelsea). Mourinho has not told me anything.
"I'm here ready to play. I've had some problems but it's getting better. I've already played three games in a week and the coach (Vincente Del Bosque) knows that I carry some problems but I will treat them during the week."