Juan Mata has admitted a friendly rivalry is gearing up among the Spain players involved in the Manchester derby, reports Sky Sports.

Manchester United team-mates Mata and David de Gea are with the Spain squad - which also includes Manchester City's Diego Nolito and David Silva.

Mata says the Spain quartet are all focused on international duty but conceded jokes have already been exchanged as the highly-anticipated match approaches.

"All of us are fully aware that this is a very special game, yet we have to understand that these are three points and don't get too crazy," Mata said on his official website.

"Both teams have started the Premier League well and the expectations are high, as everybody can imagine.

"David de Gea and me have been joking with Nolito and Silva in the last few days, although the truth is we are now focused on the games with the national team.

"After that, we will have plenty of time to think about this exciting derby."