"It was a very difficult summer because half the dressing room wanted to leave," he told French radio station RTL, according to The Guardian.
"You're preparing for a season where you don't know who's going to come in, the players who are staying are asking themselves what's going on at the club, you've got a pre-season tour of Asia.
"It was extraordinarily difficult. What saved us is that we're a club that are extremely solid and united. Other clubs would surely have gone to pieces in those circumstances."
However, Wenger conceded that the difficulties have translated into a poor start to the season, including a 8-2 defeat to Manchester United, and they now face a battle to ascend the league rankings.
"The problem is you can only climb the table slowly," he added. "We're not too far away in terms of points from fourth place. We're too far away from the top two."