The 25 year-old midfielder has been selected to play in Spain's upcoming matches against Equatorial Guinea and South Africa despite his inconsistent game time under Jose Mourinho at Chelsea.
But Mata is only worried about what Spain's head coach Vicente del Bosque thinks about his form as the World Cup finals creep closer.
"The last word on those called to the national squad is with the national coach," the playmaker said.
"He knows my strengths and what I can contribute.
"With each call I receive I go with the ambition I had with the first one.
"It is true that I have had fewer minutes but I feel fine. I try to do my best with my team (Chelsea) and with the national team."
The Spaniard has refused to let his inconsistency at Chelsea dampen his enthusiasm for the World Cup.
"It is impossible this year not to think about the World Cup and I hope that I can be there. From the age of 20 I have gone to all the major championships," Mata said.
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