The Brazil striker has been superb since his summer arrival with the Blues.
Pedro faces his former club Brighton today and Maresca said: "We knew that Joao was a very good player. The scouting department did a fantastic job because they knew him very well from Brighton.
"We are very happy with Joao. Since he arrived, he has played almost every game. In some moments, we need to think to give him some rest, but we are very happy with Joao."
Maresca continued: "He can solve situations and problems in games.
"It’s very important. That’s why we used Joao Pedro against Fulham and West Ham as a second striker, because he can also play between the strikers and midfielders.
"Until now, since the Club World Cup, he has helped us a lot, and we don’t have any doubt that he will continue to help us a lot this season. He’s a very good player."