McManaman escaped punishment for a forceful late challenge on Massadio Haidara that left the young Frenchman with suspected knee ligament damage.
Martinez has insisted that McManaman is not a malicious player and did not go into the tackle with any intent to hurt the player.
He told Sky Sports News: "Remember it's Callum's full debut in the Premier League. I haven't seen the replay.
"I believe that he touches the ball and then it's a bad challenge, but it's nothing malicious, he's not that sort of boy. It's the normal enthusiasm that you get in your debut.
"I can't really comment too much because I haven't seen the action but I can guarantee that Callum McManaman is a young man full of talent and in his debut probably showed the enthusiasm that you expect, but he's not a malicious player. If Callum hasn't apologised yet, then he definitely will do that because we're a football club where those values are very important."
Wigan managed to claim an important victory against the Magpies thanks to a late winner from Arouna Kone.