Chelsea were hammered 3-0, with a downbeat Palmer being told to acknowledge the away fans at the end.
Asked if he saw the incident, Maresca insisted: "No. To be honest, no.
"Football is a team, it's not tennis. It's not only Cole Palmer. We are all the same in this moment. We feel upset and we feel especially very sorry for the fans that were here. But in general for our fans because we cannot offer this kind of performance with 13 games to go.
"I think also in one way we can show the desire of Cole to improve things but in the same moment it's not just about Cole. It's about all the players that in this moment when you don't win the game, it's a bit like I said before with the fans, when you don't win the game it's normal that they're not happy.
"When we win games everyone is happy and the players are exactly the same. When we don't win they feel frustrated.
"We need all of them, in this moment, to be more positive because this is a moment where we need to stick together and try to finish in the best way."