Diego Costa
Costa has been struggling with a persistent hamstring problem this seasonReuters

Chelsea striker Diego Costa says that he will not risk his fitness and play for Spain in the upcoming 2016 Euro qualifiers if he is not a hundred percent fit.

The 25-year-old striker, who arrived from Atletico Madrid for a transfer fee of £32 million this summer, has been in fine form for Chelsea this season, leading the Premier League scoring charts with nine goals from seven appearances.

However, the Brazil-born striker has been struggling with a nagging hamstring problem, with Chelsea boss Jose Mourinho recently revealing that Costa is barely training.

Although Chelsea would have wanted Costa to rest and receive treatment during the international break, the striker was called up by head coach Vicente del Bosque for Spain's upcoming 2016 Euro qualifying fixture against Slovakia and Luxembourg on 9 and 12 October respectively.

But, Costa says that he will only be playing for Spain if he feels fully fit, insisting that Chelsea boss Jose Mourinho did not influence his decision.

"I don't want to be in the middle [of Spain and Chelsea]. Mourinho has not told me anything. One has to take into account that many times I am the one that makes the decision depending on how I feel," Costa told Spanish newspaper Marca.

"Here I have the confidence of the coach, the technical team, and if there is a problem I tell them. If I'm here and I'm injured then I don't play because it would be worse."

However, the former Atletico Madrid striker, who linked up with his international teammates on Monday, says that he is ready to play for Spain if he regains his fitness.

"I'm here ready to play. I've had some problems but it's getting better," he added. "I've already played three games in a week and the coach knows that I carry some problems but I will treat them during the week."

Meanwhile Chelsea captain John Terry has contradicted Mourinho's claim that Costa is "doing almost nothing in training", insisting that the striker has been looking fine at Cobham Park.

"I'm not sure where that's coming from. He certainly isn't showing that against me in training. He is training every day, he looks sharp, he looks angry, he looks aggressive. He's fit at the moment and that's the main thing," Terry was quoted as saying by the Telegraph.