Diego Costa injury: Jose Mourinho reveals Chelsea striker does 'almost nothing' in training

The Spaniard has made a massive impact since his arrival

Diego Costa (Getty Images)

Diego Costa is "doing almost nothing" in training, according to Chelsea manager Jose Mourinho.

The Spain international continued his brilliant run of form since his arrival from Atletico Madrid with his eighth Premier League of the season in the 3-0 win over Aston Villa.

However, despite such a fantastic goal return from the 25-year-old there are concerns over his fitness.

Mourinho recently said he was incapable of playing more than once a week due to a hamstring concern. Following yesterday's victory that kept Chelsea at the top of the league, the Special One told how little Costa has been able to do in training.

"He cannot be on top of his game," said the Portuguese boss.

"He's doing almost nothing in training. He's just resting and recovering from the tight muscle he has."

Mourinho added: "I don't care about Diego's goals. For me it's important that the team score enough goals to win.

"I know a striker scoring goals is always nice for him and for his confidence, especially for a player like him who is not training as he should, because we are protecting him in certain situations."

Chelsea play Sporting Lisbon in the Champions League on Tuesday, a match that might be too much for Costa although Mourinho said he hopes he can select the striker. "Let's see what happens," said Mourinho.

Yet the Chelsea manager is not keen on Costa linking up with the Spanish national team during the international break next month.

"If he doesn't go to the national team and if he stays here for 15 days just on treatment, he has the perfect chance to be top for Chelsea and top for the national team," he said.

"If he doesn't have this period, it will be always, plays one game, the other is in trouble, the muscle is tight, the muscle is in danger of rupture."

Spain have a Euro 2016 qualification double-header against Slovakia and Luxembourg.