Chelsea manager Jose Mourinho is “not happy” about Diego Costa’s injury struggles and says he cannot reassure fans that the striker will have an injury-free season.
The Spaniard was not named in Chelsea’s squad for Sunday’s FA Community Shield defeat by Arsenal at Wembley after suffering a hamstring injury during pre-season.
“Last week he couldn’t play in the Community Shield game. He was not ready to be involved,” said the Portuguese boss, 52.
“I cannot reassure fans he will always be fit but I can assure them he is working well and hard and everybody around him is helping him.”
Chelsea entertain Fiorentina in their final pre-season game on Wednesday and kick-off their Premier League title defence against Swansea City on Saturday.
Mourinho may have to retain Loic Remy in a starting role against the Swans as the forward is likely to miss the game due to the problem.
“A player that didn’t finish the season and doesn’t start the season obviously doesn’t make me happy,” he told talkSPORT.
“The boy is trying but he has a problem against Barcelona, the next day the scans show there is no injury so the next day he trains but the next day he is not comfortable 24 hours before the game we don’t know if he plays or doesn’t play.
“It is not good feeling for him, it is not a good feeling for me.”
Costa was Chelsea’s top scorer last season after scoring 20 goals in the Premier League, but missed the latter stage of the campaign due to a lingering hamstring problem.
“Am I concerned? I don’t like the word concern because I have other players,” continued Mourinho. “I don’t like to cry or moan about players that don’t play. But obviously in such a short squad like we have, then when somebody is missing I am not happy. But it won’t be an excuse for me.”
Costa, who joined Chelsea from Atletico Madrid last summer, also scored in the League Cup victory over Tottenham Hotspur in March as Chelsea completed a domestic double.