The midfielder has thrived since his arrival from Valencia.
Mata, 23, admits even he is surprised how quickly he has adapted and said: "My experience so far has been incredible. I was able to score against Norwich and Bayer Leverkusen and the reaction to me was fantastic.
"The atmosphere in general is brilliant and I've received a lot of support. I'm quite lucky in that I can play in different positions, so I can adapt to the game and develop my own style depending on the opponent. It very much depends on the game and you have to adapt each time you play, depending on the team-mates that you have around you and where they find themselves.
"It also changes if you are playing against a more closed defence or a more open team. It's clear that I can learn a lot from my team-mates in similar positions like Florent Malouda as a winger and Frank Lampard as a midfielder. Working alongside all these players is giving me the opportunity to improve; it is good for the team to have so many good players in every position."