Chelsea star Juan Mata has revealed his shock at being axed from the Spain squad but has vowed to return.The form of the 24-year-old midfielder has been a key factor in the Blues moving to the top of the Premier League table.And the former Valencia man also scored in the final of Euro 2012 as Spain crushed Italy 4-0 in Kiev in July.But coach Vicente Del Bosque has not selected the player for the forthcoming World Cup qualifiers against Belarus and France - and Mata's disappointment is obvious."I was excited about these games and confident I would make the squad," he said, quoted in The Sun."I've not spoken to the manager. The only thing I can do is keep playing well in order for him to pick me."