Costa will face City vows Mourinho

COBHAM - Diego Costa will face Manchester City on Sunday despite Jose Mourinho admitting the Chelsea striker needs rest to clear up a hamstring problem.

Mourinho revealed this week the forward started Wednesday's Champions League clash with Schalke on the bench because Costa's condition means he is unable to play more than once a week.

But the striker -- who suffered the injury during the recent international break with Spain -- will return to the starting line-up at the Etihad Stadium as Chelsea seek to extend their perfect start to the Premier League season with a fifth successive win.

Costa has scored seven goals in four Premier League games following his is £32 million ($53.1 million) pre-season move from Atletico Madrid, highlighting why Chelsea manager Mourinho is so keen for the forward to start against City.

Mourinho, though, conceded Costa's starting appearance against Premier League champions will mean he is unable to face Bolton in next week's League Cup clash.

"Diego is not in the best conditions, but he will start the game," Mourinho told reporters at Chelsea's Cobham training ground, south of London, on Friday.

"He plays this game, he cannot play against Bolton. It's as simple as that."

When asked if the player would benefit from two weeks complete rest, Portuguese boss Mourinho added: "Yes."