The £37m midfield man was snubbed by Spain boss Vicente del Bosque, leaving the ex-Chelsea ace with a two-week break from action.
And with a host of United stars jetting off across the world to represent their countries, Mata has revealed what the remaining players at Old Trafford have been getting up to.
"As you can imagine, this has been a quiet week due to the international break," he wrote on his blog.
"We have had some training sessions to maintain our physical level during these days, also with an eye on our next game at home against Aston Villa.
"I take these quiet days to keep working, as I said, but I also switch off and rest a bit.
"I’m writing these lines from Asturias, my place to switch off from football.
"Coming back home is always special, I love to see my family and friends and recharge the batteries for the rest of the season."
Mata also vowed to fight his way back into the Spain squad.
"As I always say, I have been very lucky to play and to win a World Cup and a Eurocup, to participate in the most important competitions, but I’m still excited as the first day.
"I am convinced that I’m in a perfect age in my football career and I look forward to keep contributing and achieving more success with my national team.
"That’s what I work for every day, training and playing to the maximum, trying to do the best I can.
"After that, obviously, the manager is the one who picks the players for every game."
