There were doubts about Enzo's future at the start of the season after the Argentina players taunting great rivals France following their triumph in last summer's Copa America.
But Enzo is now a first-choice for Maresca and has also worn the captain's armband.
Asked if the improvement has come from on or off the pitch, Maresca said ahead of tonight's visit of Manchester United: "It's both.
"At the beginning, because he was playing in one way all his life, previously with Benfica in Argentina, with us it's more understanding where he has to stay and where he has to arrive when we are attacking.
"I think he scores goals but also in terms of assists he has important numbers.
"I don't have any doubt that starting next season, from the first game, he can improve his numbers even more."