"I don't share the view that Gallas is a bad captain. He is a captain who is very committed and tries to work hard for the team," said Wenger, speaking at this week's forum for Arsenal shareholders.
"That would be too easy as an excuse because there are other incidents. That would be a cheap excuse.
"At the time [of the Birmingham game] we were five points in front and everybody had been praising his captaincy.
"I believe we all make mistakes and we had to come back as a unit and try to win the championship."
However, Wenger would not commit on just who would wear the armband come August.
"It [the captaincy issue] has been raised by a lot of newspapers, but I must say I have not looked at the situation yet," he said.
"My priority is to keep this team together and then we will see where we go for next season."