Chelsea star Mata: I haven't been that good
Mata has played an integral role in the club's promising start - scoring four goals, including the winner in last weekend's win at Arsenal.
But the Spain international insists there is more to come, saying: "Have I played better? Yes, I think so.
"I played well against Stoke, then Wolves, then Arsenal and now in Denmark. I'm feeling very well but I want to feel better and improve as well."