Chelsea manager Jose Mourinho has said Diego Costa is unlikely to return before the end of the month.
Costa had to be replaced shortly after coming off the bench during last weekend's 2-1 win over Stoke as he suffered a recurrence of his hamstring injury, and now looks set to miss this month's games against QPR, Manchester United, Arsenal and Leicester.
However, Mourinho said he expects that the Spain international, who has scored 19 goals in 24 Premier League appearances this season, will be back for next month's games against Crystal Palace, Liverpool, West Brom and Sunderland.
"We have eight matches to play," he said. "If he plays four, it's normal. If he plays three, it's a little below what I am expecting. If he plays five it is more than what I am expecting, so I am thinking about four matches."
However, Mourinho reported better news on the rest of the squad, with John Obi Mikel available again and Cesc Fabregas set to play with a face mask.
"Only Diego is injured," Mourinho said. "Everybody else is fine and ready. Mikel is ready, Fabregas with a mask is ready too. No problems."
Fabregas and Nemanja Matic are both a booking away from a two-match suspension but, even though that would see the midfield duo miss the games against United and Arsenal, Mourinho said: "They will both start
"It's always the same. We try not to get yellow cards during a match. We try to play football. To have an idea, in the last match our opponent made 22 fouls, we made five -- it's been like this for almost the whole season.
"If they [Matic and Fabregas] have to make a foul for a yellow card -- a foul you have to do -- they have to do it, but the way we play it's not easy for our players to be booked."
Chelsea are currently seven points clear at the top of the Premier League and have a game in hand on all of their title rivals, but Mourinho said: "The game is a three-point game.
"We need points, we need victories and we cannot choose matches. It doesn't make any sense to think about some matches and not about others.
"This is a three-point match and we have to play with our maximum power to try to get them."