Diego Costa doing 'almost nothing' in training, says Jose Mourinho

Diego Costa is barely training despite leading the race for the Premier League Golden Boot, according to his Chelsea manager Jose Mourinho.

Costa's eighth goal of the season set up Saturday's 3-0 win over Aston Villa, but hamstring problems are said to have limited his involvement 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."

Mourinho also reiterated his concern for the forward - a £32m summer buy from Atletico Madrid - if he is selected for Spain's Euro 2016 qualification double-header against Slovakia and Luxembourg in October.

"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 added.

"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."

Despite the fitness issues, Mourinho hopes to select Costa to play against Sporting Lisbon in the Champions League on Tuesday.

The Portuguese added: "I want to. Let's see what happens."

Costa scored the second and helped create the third for Willian, after Oscar had given Chelsea a seventh-minute lead.

The win helped maintain their three-point lead over Southampton at the top of the Premier League.

"We go match after match," said Mourinho. "The next one for the Premier League is Arsenal [next Sunday].

"We have a lead of three points over Southampton, which is a guarantee that next weekend we will still be top of the league.

"Is this very important? It's not crucial because it's too early, but it's a little bit of a space that gives you that good feeling that you're top of the league. It's good to be there."