Jose Mourinho defends Drogba selection in game against Schalke 04: Diego Costa wasn't fit enough for the game

Chelsea manager Jose Mourinho says Diego Costa did not start his side's opening Champions draw with Schalke because the striker was not fit enough.

Mourinho's side laboured to a 1-1 draw at Stamford Bridge on Wednesday, but wasted several clear chances to kill the game off.

Despite scoring seven goals in his first four games for the club, Costa was only named as a substitute as Mourinho opted to start Didier Drogba instead.

"Costa has a problem," Mourinho said of his striker. "If he has one week to let the muscle recover he can start a game. Playing on Saturday, three days is not enough for him to recover.

"It was not to protect for the game Sunday [at Manchester City], it was because today he was not in condition to start the game."

Costa replaced Drogba shortly after Schalke equalised through Klaas Jan Huntelaar, but the Spaniard failed to make an impact.

The forward sparked fears after he withdrew from the Spain squad to face Macedonia in the recent international break, citing a hamstring injury.

Mourinho, however, quashed worries over Costa's fitness before the striker returned to score a hat trick against Swansea last weekend.

Now though, the Blues manager says midweek games will be a rarity for the 25-year-old.

"He played here one match and he was perfect," Mourinho said. "He went to the national team and after the game against France he came back to us injured. He came to us [from Atletico] and he was completely fine. He had a problem again in the national team, not with us.

"Now we have the problem and now we have to resolve the problem the best we can. Today he was not in condition to play. Sunday we believe he is.

"Next week against Bolton [in the Capital One Cup] for sure he isn't. We have to manage the situation until the moment he's completely fine. If today he starts the game, for sure he cannot play on Sunday. We have to go step by step."