The Argentina international had come in for criticism after scoring just once in five appearances prior to Wednesday's UEFA Champions League triumph over Massimiliano Allegri's men.
But Messi allayed fears over his recent form by firing the Catalan giants ahead from the penalty spot, before re-establishing Barcelona's two-goal cushion when scoring the third in the closing stages after a Gerard Pique own goal had given Milan brief hope.
The win secured Barcelona's progression to the last 16, and Neymar praised the impact of the reigning FIFA World Player of the Year.
"Lionel Messi is a great player, a genius" said the Brazilian. "He's the best in the world. I think that he can win another Ballon d'Or.
"I'm happy because we won and that we secured a spot in the next round. We still have a way to go, but the most important thing is to keep on growing as a team."
Team-mate Xavi echoed Neymar's sentiments, and he believes that Messi has been the victim of the exceptional standards he has set throughout his career.
"I think Messi is playing well," said the Spain international. "Everyone can always play better football, and he's set the bar very high.
"I'm happy that we won. We played a good match, it got a bit complicated when they scored but we could have won by a wider margin.
"We will try to play at an excellent level in order to secure good results. We're on the right path."
