Manager Jose Mourinho says striker Diego Costa has suffered a hamstring injury in Chelsea's 3-2 away win at Hull City.
The Spaniard scored his 20th goal of the season in all competitions but was forced off the pitch late in the game with Loic Remy and Didier Drogba set to cover in the offensive department during the absence of the 26-year-old.
"It's a hamstring injury [for Diego Costa]," Mourinho said.
"When a striker is playing, the team needs a goal to win the game and he says it's over for him, it's over.
"He tried to play the Champions League final with Atletico and was injured, he has that fragility, we know his hamstring is not a strong one.
"He works hard in the week to compensate for the weakness he has there but the injury can come. We have Remy and Drogba, we never cry about injured players so let's move on."
Meanwhile, Mourinho explained what went wrong when Hull City restored parity in the 28th minute of the game.
"If we tell our goalkeeper every time he has a back pass to kick it in the stands the second goal wouldn't happen but we don't do that," Mourinho said.
"He tried to play, lost the rebound, the defenders didn't open a passing line to play from the back and it's a goal. Everybody was unhappy.
"It was just a question of stability, emotional control and playing."
