Jose: Duff needs to build up his strength

Jose Mourinho has warned Damien Duff that he cannot expect an instant return to Chelsea's first-team.

The Republic of Ireland winger continued his rehabilitation from a shoulder injury by playing for 90 minutes in a friendly against Bulgaria on Wednesday, but will not be considered for tomorrow's trip to Birmingham.

Mourinho, who earlier this week said the player was suffering from a "mental block", feels that Duff needs to experience more physical contact before he is ready.

He said: "It's fantastic that Damien played 90 minutes for his country but it doesn't mean he's ready to play for Chelsea. A friendly is a friendly and not the same as playing in the Premiership. He was fit to play for me against AC Milan but not against Manchester United.

"He has to play. He has to be kicked, he has to fall and he has to put up with nasty contact. He needs to build up confidence in his shoulder. He's been out for several months and needs to build up his strength."

Duff trained with Chelsea yesterday and could return to the substitutes' bench against Crystal Palace on Tuesday. Arjen Robben (ankle) also misses the match at Birmingham but Joe Cole has fully recovered from a sore foot.

Mourinho said: "Damien's a great player, a player that I want and need. Without Arjen Robben I need him even more because they're players from the same position.

"I need him back in good condition. Perhaps Crystal Palace and Southampton next week will be good games for him."