LONDON (AP) -- Chelsea manager Jose Mourinho says Diego Costa could miss the team's next four games with a left hamstring injury that has affected the Spain striker all season.
Costa, who has scored 19 league goals, limped off after a recurrence of the injury during Chelsea's 2-1 win over Stoke on Saturday.
Mourinho says "we have eight matches to play -- if he plays four, it's normal. If he plays three, it's a little bit below what I'm expecting."
Chelsea leads the Premier League by seven points, with a game in hand, and plays Arsenal and Manchester United -- its two closest challengers -- in the team's next four games.
Chelsea plays west London rival Queens Park Rangers on Sunday.