Kovacic has discussed the differences between Tuchel and previous boss Frank Lampard.
He told the club's website: “I think we've improved a lot in the last three games, we've got seven points. But we need to go game by game and try to be as up as possible and I think we can do it.
“I think we have little problems – we didn't score against Burnley as well. In the last 15 minutes we were 1-0 up and it could be even more.
“This is a thing we need to improve, to finish games. I think this is one thing we will work a lot on.
“He [Tuchel] explained to us what he wants. It's exactly that – to play fast forward, to create chances, to be in the opposition's half.
“I think we've improved a lot in the last three games but I think we can be even better & be even more confident.
“In the games coming, we will be even better and we need to even better because we can do it."