Diego Costa
Costa has netted 24 times this season but might not be at his best against PSG, Mourinho warnsGetty Images

Chelsea manager Jose Mourinho has warned that Diego Costa will not be at peak fitness for the Champions League trip to Paris Saint-Germain after three weeks out through suspension.

Costa has not played since the League Cup win over Liverpool on 27 January, missing the games against Manchester City, Aston Villa and Everton having been banned for stamping on Emre Can.

Though the Spain international's first season in English football has been dogged by injury concerns, with a hamstring problem seeing him miss games throughout the campaign, an extended spell of rest has given Costa the chance to recuperate.

However, Mourinho says that the Chelsea forward has spent too long out of action and that could affect his performance as the club travel to the Parc des Princes on Tuesday (17 February) for the first leg of their last 16 clash.

"He will start but a long rest is not good for him," the Chelsea boss said."I don't think it's good for a player to be three weeks, or three matches, without starting a game. So I don't think he'll be in the best condition.

"A little rest is welcome for everyone; a big rest isn't good for the players. So we are not going to see the best Diego. I hope I'm wrong, but probably he will need this game to try to get back to his best.

"We organised a game three or four days ago with the kids for him to compete in. We tried to replicate competition for him but it's different.

"I know he has hunger to play, a big appetite to play, and the Champions League scenario is a scenario that every player enjoys.

"And, at the same time, [Loïc] Rémy and [Didier] Drogba have played in the last three matches. Obviously it's important for them to have had minutes and confidence and I know that I have them both ready for the game, too."

The Brazilian-born forward has enjoyed a fruitful first season at Chelsea since joining from Atletico Madrid, scoring 24 goals in all competitions to help the club fight on three fronts this term.