Wenger’s current deal runs out at the end of this season and there has been speculation that he could leave after 21 years in charge.
“Maybe it is time to change something at the end of the season,” Gallas told talkSPORT.
“We can’t forget what he did for the club. He did a very, very good job so sometimes you can’t sack the manager like this. You have to respect the manager.
“That is why I said at the end of the season maybe the board has to speak with Arsene and try to find a solution.”
Gallas also stated that Wenger is being criticized a lot, because of the lack of trophies in recent seasons.
“You get criticism when you don’t win trophies, when you don’t win games, and that is maybe the difference between Jose Mourinho and Arsene Wenger,” he continued.
“Mourinho wants to win every game and at the end of the season sometimes he has success but, for Arsene, Arsenal didn’t win from 2004 so everybody starts to criticise him because football has changed.
“Football is about victory, about trophies. Players want to lift trophies. If you don’t lift a trophy in your career, you will feel disappointed at the end of your career.
“I don’t know what Arsenal are going to do but they have to win trophies again.”