"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.
"He had an outburst at Birmingham, but I still believe today that, even if that was a mistake, that was not why we did not win the championship.
"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."