"We have know each other since we were 15 and in the Spanish youth teams," said Mata.
"We have a good connection on and off the pitch and I think he will give us a lot of good things this season.
"He can play quick, slow, dictate the rhythm of a game. He can score as well. He is a complete midfielder and can bring these qualities to the team.
"I enjoy playing with quality players like him and Wayne. We try and play the same way. Hopefully we can do good things for the fans and the club this season."
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