The 25-year-old has struggled for regular football at his club this season, but is in the latest Spain squad for their upcoming friendlies against Equatorial Guinea and South Africa.
"The last word on those called to the national squad is with the national coach. He knows my strengths and what I can contribute," Mata told reporters at a press conference.
"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 and with the national team.
"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 has won 30 caps for his country.