Palmer has been Chelsea's outstanding player in their unexpected rise to second place in the Premier League.
With 11 goals in 15 games, the England international is Chelsea's top scorer and has also provided six assists.
Palmer's confidence and quality were on display once again with the cheeky chipped penalty in last weekend's win at Tottenham.
It was the kind of eye-catching moment that Maresca claimed as evidence that the 22-year-old is a truly unique talent.
"I feel very proud and privileged to work with Cole. Cole is a different one to the rest," the Italian said.
Chelsea host west London neighbours Brentford on Sunday looking to keep up the pressure on Liverpool in the title race.
The Blues are four points behind Liverpool, who have a game in hand, and are also looking to qualify for the Champions League.
Palmer will be key to Chelsea's hopes of keeping pace with Liverpool and returning to Europe's elite club competition.
Maresca, who worked with Palmer during his time in charge of Manchester City's Elite Development Squad, praised his forward's ability to handle the pressure and expectations of being Chelsea's main man,
"Many top players have that way," he said. "They look like they almost don't care but it's just their way and being in that way gives them more freedom.
"They can relax and you can see Cole is the same way. Cole was this way five years ago and he's still the same."
Asked whether he believed Palmer is the best player currently playing in England, Maresca said: "At this moment, he could be, but England are lucky because there are so many good players and Cole is one of them. There are so many good players in the Premier League.
"Absolutely he can be world class but as you said, he is only 22 and there are many things he can improve, including that at the moment, everyone is marking him man-to-man, but there are many things he can still improve."
© 2024 AFP