Di Matteo has already suggested that he will have a clear out at Villa, as he wants to trim his squad.
The Italian boss feels that Villa’s squad is bloated, and a number of players are expected to depart in the summer.
However, Di Matteo insists that Grealish is one of the members of Villa’s squad that he wants to keep around.
"I know all about him. I've done all my research on him,” the former Chelsea boss said.
"Don't worry about that. I'm not going to go into details about where I see him playing right now – that would be wrong.
"I think you need to give it a bit of time and you will all see.
"What I will say is that I think he is a talented boy and I think he has a future here.
"Let me work with him a little bit. Ultimately, it is always down to the person.
"But do I think there is a player there? Yes. But it is down to him as well.”
Grealish has been linked with a host of Premier League sides, following Villa’s relegation from the Championship.
The likes of Stoke City, Tottenham Hotspur and Everton have all been credited with an interest in Grealish by the Telegraph.
Stoke, Tottenham and Everton believe Grealish has the ability to play in the top flight.
Grealish made a minimal impact for Villa last season, making just 16 Premier League appearances for the Midlands side.