Wenger: Asia tour crucial for Diaby fitness
Diaby made just five appearances for the North London club last season, having suffered injuries to his hamstring, groin, calf and thigh over the course of the campaign.
This often left Wenger short of options in central midfield, with Jack Wilshere sitting out the entire season with ankle and knee injuries.
But with Diaby now seemingly on the road to recovery and travelling to Asia with the rest of the Gunners' 24-man squad last week, the Arsenal manager is understandably delighted.
"You can't imagine how happy I am firstly to have him in the squad, because he is an exceptional player," Wenger told Arsenal's official website. "I am cautious but confident because he had two hard weeks and came through it well.
"This tour is another decider for him. He will play on Tuesday night and now it is down to uncontrolled movement in games: how does your body react to that? I am confident with what I have seen in training that he will do it."
The news that Diaby could soon be back in regular action is not just a boost to Arsenal, but also to France.
The midfielder was forced to withdraw from Les Bleus' Euro 2012 squad, and Wenger believes the 26-year-old can be a key player for club and country.
"He is the first player who would be on the France team-sheet in midfield when he is fit. Laurant Blanc said that before the European Championship and he waited a very long time to know if he could play or not. But he couldn't."
Arsenal will kick off their Asian tour with a match against a Malaysia XI on Tuesday, before facing Premier League rivals Manchester City in Beijing on Friday.