Jose Mourinho has told stuttering Chelsea striker Diego Costa that he must read the game better in order to rediscover his talismanic form of last season.

The 27-year-old, who has netted four times in all competitions so far, had a touchline row with Mourinho during the 4-0 Champions League win in Maccai Tel Aviv this week.

Costa found the net on 20 occasions in a goal-laden first season with the Blues following a £30m move from Atletico Madrid, and the Portuguese manager demands that same sharpness.

"He's not reading the game properly in these actions," he is quoted as saying by The Guardian.

"That was my opinion. As a striker he must read; you have to play not when you have the ball, but when others have the ball. You have to anticipate things and read the game faster.

"Everything is an accumulation [of confidence]. You're not on fire again just because you've scored a goal against Norwich. It's a process."

Costa has scored seven times in 10 months for Chelsea.