Speaking in an interview with Spanish publication AS, the playmaker stressed he was happy in England but revealed his uncertainty about the future.
"I don't know," he said.
"I've been in England for a good while, in a league that I'm well accustomed to and where I've adapted well, but it's true that times you miss home, your family, your friends.
"But I don't know if I'll return to Spain in the near future.
Man Utd transfer news: Juan Mata could leave for free in the summer (Image: GETTY)
"I'm calm [about the situation at United]. I'm at the fantastic club that is Manchester United, one of the biggest in the world.
"I have to think about the short term and do well from now on."
Mata has been with his United team-mates in Dubai this week taking part in warm weather training.
And Paul Pogba says the players have been thoroughly put through their paces by coaching team.
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Man Utd transfer news: Juan Mata and David de Gea during training in Dubai (Image: GETTY)
“It’s not a holiday, we came here to work,” said the Frenchman.
“We don’t get this kind of weather a lot in Manchester, so obviously to get this weather and vitamin D is always good. It’s good for the head.
”The training is intense as we’re preparing for a big game [against Tottenham], so we need to be ready.
“We've had good conditions to do some hard work and when we go back we’ve got a fresh mind and fresh air and we come back to focus even more.“
In-form United face Tottenham at Wembley on Sunday.