MANCHESTER, England (AP) -- While he sat on Chelsea's substitutes' bench this season, Juan Mata could see his chances of playing for Spain at the World Cup slip away.
Mata already had been dropped from Spain's roster once this season and with the country blessed with so many playmakers, he was in danger of being overlooked for the defending champions' 23-man roster for the tournament in Brazil.
That was one of the key reasons Mata pressed for a move from Chelsea once Manchester United showed interest in signing him.
''It was really important,'' said Mata, who completed his 37.1 million pound ($61.2 million) switch to United on Saturday. ''The Spain squad is really difficult to get into, there are a lot of players fighting for positions to be in the last 23 going to Brazil. I hope this is a great chance for me to keep playing, keep fit and show the manager of the national team I want to be there, I have to be there. I don't know what would have happened if I had stayed at Chelsea.''
The likelihood was Mata would have remained on the bench behind Chelsea manager Jose Mourinho's preferred attacking trio of Eden Hazard, Oscar and Willian.
Even Andre Schuerrle was seeing more game time than Mata, whose last match for Chelsea was on Jan. 1 against Southampton. Mata was taken off just after halftime and showed his displeasure.
''Now I am here. Now the moment is here,'' Mata said Monday at his presentation by United. ''Now I'm trying to play as much as I can to help the team, and if things are good in the final part of the season, the World Cup is going to be closer for me, for sure.''
Mata, a 25-year-old mifielder, was Chelsea's player of the year for the past two seasons.
''I got wind a month or two ago that it could be a possibility,'' United manager David Moyes said, ''but I never believed we would pull it off. I have been saying that I didn't think we would get a chance to do much business in January - I didn't think the players we would be interested in would be available. But when we got the sniff that Juan would be available, we went after it right away.''
Moyes has to decide where to play Mata, whose best position is a central role behind the forward. He has big competition at United for the ''No. 10 role'' in Wayne Rooney.
''I can't wait to play alongside him,'' Mata said. ''For me, he is one of the best players in the history of this country, he is unbelievable.''
After winning the Premier League title by 11 points last season, United has slumped to seventh this season, 14 points behind first-place Arsenal and six back of fourth-place Liverpool - England's last Champions League berth.
''I like the pressure. I think it is good for a footballer to try and improve when you have pressure and people are expecting big things from you,'' Mata said. ''And I am really looking forward to it, to try my best and help the team and make these amazing fans happy.''
At least he will be spared the pressure of wearing the No. 7 shirt at United made famous by George Best, Bryan Robson, Eric Cantona, David Beckham and Cristiano Ronaldo.
United said Mata will wear the No. 8 jersey, taking it over from Anderson following the Brazilian's move to Fiorentina.