The Latics striker forced the Frenchman off the pitch in the first half of Wigan's eventual 2-1 home victory with what many believe should have been a sending off but Martinez says his player was not malicious and simply trying to do everything he could for his team in his first Premier League start.
"Remember Callum McManaman was making his full debut in the Premier League and, as a young man, you know you are going to give your life for everything," said the Latics boss.
"I haven't seen it but I believe he gets the ball and then it's a bad challenge.
"No-one wants to see that but I guarantee that is just a striker trying to win the ball over-enthusiastically because he is making his (full league) debut.
"What you need to look at in those incidents is if there is intention, a nastiness about the tackle. We are not a nasty team.
"He has not a nasty bone and is not bad-intentioned. The referee was in a perfect position, he is looking at the incident, where the ball is and where the ball is hitting.
"When you get the ball and then there is a follow-up it is very difficult for a panel to punish that."