Mudryk scored in the 4-1 victory on the night.
Maresca later said: "Very happy, not for me but for him. We as a staff, we spend a long, long time to help the players; not only Misha but the whole squad. Since we started, we are working with Misha and all the wingers to arrive in the box, into the position where Misha scored.
"He struggled to arrive there and now he is starting to arrive there. That is where we are going to score goals.
"We want the best for Misha. Since day one, we are trying to help Misha. Probably for him, he is one of the guys that the learning process is more slow compared to the rest but he is improving. I'm sure that slowly, slowly we will have Misha scoring more goals and being important for us."
On Renato Veiga's performance at centre-half, Maresca added: "I just said to Renato, he has played already as a centre-back, a full-back, holding midfielder, attacking midfielder. He has already played four or five positions. One of my first press conferences, I said that the reason why I really like and love Chelsea is because many players can be versatile.
"Today, in my idea, if they can play different positions, then it is better for the team and especially for the players. Today, if you just play one position, I don't think it's enough. You need to learn more positions."