Diego Costa
Diego Costa's hamstring problems have dogged the start to his Chelsea careerGetty Images/Julian Finney

Diego Costa has sent a reassuring message to Chelsea boss Jose Mourinho, claiming he will not take any risks with Spain if he is struggling with his hamstrings.

Spain manager Vicente del Bosque included the Chelsea striker for the European Championship qualifiers against Slovakia on 9 October and three days later against Luxembourg, despite Mourinho's concerns about the striker fitness.

The Portuguese manager has insisted on a number of occasions that Costa is unable to play more than once a week but handed him three starting successive appearance in the last week, against Aston Villa, Sporting Lisbon and Arsenal, stating he would not save the striker so he would be in "perfect condition" to play for the national team.

When asked about a possible war between Del Bosque and his Chelsea manager, Costa said: "I don't like being stuck in the middle of it.

"All I want to do is be a success with the national team. Mourinho hasn't said anything to me and it's also up to me to make my decisions, based on how I'm feeling, although the manager and the coaching staff do have input. If I play injured then that only makes things worse, so I won't do so if I'm not feeling right," he said, according to AS.

Costa was injured during the last international break in September, in a friendly defeat to France, with him being withdrawn from the squad for the following game against Macedonia.

"There are times when you take risks, but that's why I ended up not playing against Macedonia. I have to be careful. My injury wasn't fully cured when I left Atlético, but I'm getting better all the time," he said.

Costa is looking forward to score his first goal for Spain after failing to score in his previous five international appearances.

"I haven't scored here yet, but I've not had many chances either. I just need to work hard to get my first goal, which is exciting for me. When I have the chances, I'll be there," he said.

The striker also hopes to continue his impressive connection with Chelsea teammate Cesc Fabregas by transferring those Premier League performances to games with Spain.

"It's going really well for us at Chelsea, but we've got to look for it here too," Costa said. "He's a great talent, we know each other really well and hopefully we can get some goals together here."