Chelsea striker Diego Costa is frustrated to be out of action with Spain due to a hamstring injury.

The Brazil-born striker has been criticised for failing to show enough commitment to his adopted country's national team.

But Costa said: "I was in good form, I thought everything was finally going to work out. I really wanted to prove my form and my worth...

"My history with the national team is that it still hasn't really started. I haven't done anything yet.

"Sometimes it angers me that they put in doubt my commitment.

"I already proved that I'm enthusiastic and that I want to achieve success with the national team.

"The best way to silence the critics is to play and to do things well. But I haven't done that yet and hence, I have to listen and swallow it."