The England playmaker recently suffered a setback in his recovery from a shin injury.
Asked if Grealish is fit to play, Villa manager Dean Smith said: "No, he's not. I did say it'd be a few weeks before we got him back out again and we're still waiting for him to get back out onto the grass.
"He's itching to get in and we want him back. We've also got Trezeguet who had a nasty knee injury last week and he's going to be out for a significant time now. He's had an operation that was successful.
"Morgan Sanson's got a knee injury as well, so we're not too sure how long he'll be out."