While Wenger cannot understand why the 29-year-old decided to choose that moment, he insists his commitment to the cause should not be questioned.
"It's interesting because Santos is a player who cares. If you speak with him, he gives an image of himself which is not him," the manager told arsenal.com.
"He is serious, he wants to do well. It is about the result, about the team. [Asking for a shirt at half time is] a difference of culture.
"I can understand that an English guy doesn't understand it and I'm French and I don't understand it either. He is completely in a different world when he does that.
"But he cares and he understands today what it means and, believe me, he will never do it again. I spoke to him about it but I do not want to make too big a story of it.
"I believe that was not the right thing to do at all, but that is not an explanation of our bad performance on Saturday."