George scored a first goal for Chelsea in the 3-0 win for the first-leg of their Europa Conference League quarterfinal.
Maresca said of young winger George afterwards: "Very happy first of all for the Chelsea academy because it's one of our boys from the academy so very happy for him.
"He was quite good first half, take responsibility, second half in the middle probably was a bit better but the one that I fall in love tonight is Josh Acheampong because for me potentially he can be fantastic player, top player for this club, for the football in general and a good player show you that can play in different position and he can do good, he was full back, good, midfielder, good, central defender, good, so it's not about I play in that position or in that position, if you are good player you can be in different position."
Maresca also had a word for Christopher Nkunku after he failed from the penalty spot on the night.
He added, "Probably in this moment is lack of confidence and the reason why is because he's missing goal or penalty like tonight but the only way to deal with that is to work hard every day because when you work hard for sure the reward is important, the problem is when you stop to work and the good thing about Christoph is that he's working well every day."