Jose Mourinho rejects report claiming Diego Costa isn't happy at Chelsea

Sydney: Chelsea boss Jose Mourinho Tuesday rejected a report that star striker Diego Costa wants to quit the English Premier League champions.

A Spanish newspaper reported that the Brazilian-born Spanish international was homesick and had made contact with Atletico Madrid about a return to Spain.

Costa proved a handful before he tired and was substituted in the 40th minute of Chelsea`s 1-0 win over Sydney FC in their final match of a long season in Sydney on Tuesday.

Mourinho said reports of Costa being unhappy with his lot at Chelsea were wide of the mark.

"I`m happy he`s unhappy," Mourinho told reporters.

"He`s the guy responsible for everything good we have in the dressing room. He`s so happy, he`s so funny, he`s enjoying every minute. He makes people enjoy.

"He`s the happiest guy in the dressing room, so if this is unhappiness, I`m happy with that.

"I think he was not happy with the news, and I think in his bad English he has to try and address that he`s not happy with the news -- and not Chelsea."

Costa has been troubled by a recurring hamstring problem, and was not risked for the whole game in front of a capacity 83,598 crowd at Sydney`s Olympic stadium.

"Diego was tiring and we didn`t want to risk (it)," Mourinho said.

"I told him, `Let`s give to the fans at least half an hour of Diego Costa`. He went until minute 40 and in that time we all felt that was enough."