Pedro signed for Chelsea from Brighton during the week and is now training with the squad in the US.
The Brazil international is clear to compete in the remainder of the Club World Cup and Maresca said of his new striker: "Joao Pedro's situation is a bit different.
"He was on holiday and even if he was working, it’s not the same working by yourself compared to working with the team.
"We are very happy with Joao in the last two days he has worked with us. We will see if we need him tomorrow and if we have the chance to give him some minutes, we will give him some minutes."
On the fitness of Romeo Lavia, Maresca said: "We will try tomorrow. He had a small problem at the end of the last game against Benfica.
"It’s just a muscle problem and tomorrow we will see if he’s fit. Otherwise we will find different solutions because Moi is also suspended. So we will need to find different solutions."
New Palmer role
During the media conference, Maresca was also asked about playing Cole Palmer on the left-side of their attack.
He added: "Cole can play on both sides. He played against Benfica in the left pocket; he used to play in the right pocket. He just changed right to left. In many games in the season, he played in the left pocket, Newcastle at home is one I remember.
"Against Benfica, he started a little wider to come inside the pocket. But Cole’s position was exactly the same as last season, the only difference was he was in the left pocket rather than the right."