After joining Chelsea from Leicester City last month for around £30M, Dewsbury-Hall has played his first game for the Blues and has impressed many with his performance.
Maresca spoke about the midfielder and the nickname “teacher’s pet” which his teammates have given him.
"I did not know about this joke. From outside, you can see Kiernan is talking a different language to his teammates in terms of he knows exactly what he needs to do on and off the ball. On the ball sometimes he is going to receive it wide, running in behind.
"This is because we have worked together for one year. I asked him to speak with his teammates on the pitch because he knows exactly how we are to move and he is going to help us this season many times."
The manager was also asked about Fernandez who has been caught up in some controversy in recent weeks after returning from the Copa America.
"You can see he is a bit behind. In terms of physical condition, he was probably a bit slow. But he had just one or two sessions with us, no more than that. Today, 45 minutes was to give him another session. For us, this kind of game is also a training session and for Enzo today it has been a very good training session."
Both midfielders will be competing for a spot in the Chelsea side which is overloaded with talent at the moment. This preseason will give Maresca an idea of who is the best choice going into the new season.