Grealish extended his stay at the Villa Park earlier this week when he signed a five-year deal, ending every uncertainty about his future.
The 25-year-old scored eight goals and provided six assists as he helped the Villans to avoid relegation last season.
Agbonlahor, who played with Grealish for few seasons before he retired, has admitted he is happy to see the former Notts County man stay, and insists the Birmingham-born star is the best player he has ever played with.
I've played with some great players but for natural ability, I've got to say Jack Grealish," Agbonlahor told talkSPORT.
"I know I will upset a few players I played with but for me I've seen nothing like it.
"I mean even in training — you'll have the quickest players, the best defenders and he just runs past you like you're not even there.
“The amount of times I've tried to tackle him, in training when I played centre-back for a bit of banter.”
"I can't get anywhere near the guy so I end up kicking him and putting him on the floor.
"But it's just that natural talent he's got.”
“It’s the movement of the body, a little movement of the body and he's gone. A little bit of acceleration when he's running with the ball and he's gone.
"He reminds me a bit of like, I know it's a big statement, but Iniesta in his prime. He's just skipping past you, running past you, a little movement of the shoulders and he's gone."
