Palmer hasn't in his last 16 appearances for the Blues, though Maresca insists the drought has nothing to do with ability.
"For sure it's a mental thing, it's not tactical or technical," said Maresca.
"Cole is still the player who scored 14 goals in 20 games. The style is the same, the manager is the same, the club is the same. Nothing has changed around Cole. It's just mentally in this moment.
"You can see he's a little bit worried because he wants to help the team. You can see he's struggling a bit on that. But he showed how happy he was after Fulham. It's just a matter (if) we can win games. For sure he's going to score goals.
"If you go back game by game, he had at least every game one or two chances, so it's not about how the team is playing."