Mata played in both the European Champioships and Olympic Games for Spain, but believes that being allowed extra time off by Roberto Di Matteo has allowed him to return to Stamford Bridge ready for his second season in English football.
He told reporters: "We had a talk before the start of the season because, with the Euro Cup and the Olympic Games, it must be a hard summer for me.
"So I think it was logical. I feel really well as well because of the good run of results for the team. We stayed at the top of the league, so I'm very happy.
"Before I had these two weeks, I didn't feel bad. But I think, with so many games in the season, it will be good for me and now I feel very, very good.
"I think it was a nice break for me. Two weeks resting, trying to get out of football and now I feel really fit."