The midfielder missed more than a season of international football through injury and his comeback performance against Finland on Friday in which he scored the game's only goal showed his value.
"I hope he will go on like that for a long time because he is essential to the team," said fellow midfielder Rio Mavuba.
How long will this last is often the question with Diaby, a player whose career has been plagued by injuries.
Last season, he played only four games with Arsenal and missed the Euro 2012 finals because he was not fully fit.
"I hope it is the good comeback. Last year was not easy, I worked hard during the off season to come back strong. I hope I will not be injured this year," said Diaby, who has only won 15 caps since his first appearance in 2007.
Diaby's pace and poise proved lethal against Finland and Coach Didier Deschamps did not expect any less.
"I did not need to be reassured because I have been seeing him play at Arsenal. He has a lot of qualities," said Deschamps.
"He is an all-round midfielder. He wins the ball, but also carries it forward very well and he can score. Obviously I prefer to have him at my disposal."
Diaby could make up once again for Karim Benzema's lack of impact in the box as the Real Madrid forward has been playing more as a playmaker than a proper striker since last June's Euro finals.
"We need to be more present in front of goal," said Deschamps, who asked the wing players to move to number nine when Benzema, who set up Diaby for the goal in Finland, finds himself in a deeper position.
Deschamps also has the option of fielding Olivier Giroud, who trained normally on Saturday after missing the Finland game because of a muscle problem, alongside Benzema against Belarus.
"I'm expected to be more in the penalty area. Well, that's what I'm going to do against Belarus," Benzema told French TV channel TF1 on Sunday.
Belarus, who beat Les Bleus at the Stade de France in their opening Euro 2012 qualifying game in 2011, started their campaign with a 1-0 defeat by Georgia.