By ESPNSTAR.com staff
Diaby has long been compared to Vieira due to their similar stature and powerful playing style but unlike his predecessor, Diaby has not yet been able to hit the heights Vieira reached during his 10 years at the club.
Much of it has been down to Diaby's poor injury record; the French international has constantly found himself sidelined with injury ever since he severely fractured his ankle following a horrendous tackle from former Sunderland defender Dan Smith.
As a result, the 26-year-old has only managed to make 117 appearances for the Gunners since joining them eight seasons ago, and Vieira has bemoaned the lack of progress Diaby has made due to his poor injury record and claimed the former Auxerre man had the potential to be a better player than he ever was.
"I am frustrated and disappointed for Abou Diaby with all the injuries he suffered," Vieira told France Football.
"If he could have improved constantly, he would have reached an exceptional level.
"About his potential, he is better than me, better on a technical level, better dribbler, and better scorer too. In one word, more versatile than I was.
"Maybe I was better in terms of physical impact.
"I suppose it is very difficult for him to have not reached his best. But maybe it is not too late."
Vieira, who is now Football Development Executive at Manchester City, also revealed that he regards midfielder Yaya Toure as the best player within City's ranks.
"Yaya Toure is the one that has impressed me the most," Vieira added.
"I didn't know he would have such technical qualities when I saw him playing with Barcelona.
"But at City, he has such a power to accelerate. He bowled me over.
"And I believe he can still help to get more from the team.
"Moreover we have a very good relationship. He has big intelligence about the game. You can feel he played at Barcelona."
Arsenal will take on Aston Villa at Villa Park on Saturday with Diaby still out with injury, while Toure will be expected to start for City when they take on Chelsea at Stamford Bridge in a clash which could have a huge impact on the title race.