Wenger is angry Pearce axed Wilshere against Portugal last week following the player's arrest outside a London nightclub.
He said: "I was surprised when Pearce said that Jack has taken his eye off the ball and I am pleased with the player's reaction to being dropped.
"I have spoken to Jack this week and he is totally focused in training. He always was. He wants to do well and is a happy man on the pitch. I have not spoken to Pearce. He has to deal with the players when he has them at his disposal.
"And I deal with them when I have them.
"It looked to me that Wilshere was between the senior England team and the Under-21s. The Under-21s wanted him and then they decided not to play him against Portugal because of that story.
"As for the rest, I don't want to be involved in all that. I don't think it needs any more comment."