The Blackburn Rovers manager gave Grealish his Villa debut.
However this season he has been poor and making the headlines for all the wrong reasons. He has been banished to the Under-21s by Remi Garde after pictures emerged of him partying late on Saturday and Sunday in national papers - despite a 4-0 loss to Everton on Sunday afternoon.
The man who gave him a debut in a Villa shirt was Paul Lambert and the Scot has been speaking about the youngster today.
Now the manager of Blackburn Rovers he told Sky Sports today:
"There is more to being a footballer than just being on the pitch, you've got to live right off it.
"There's maybe one or two things there that the manager will probably deal with but you've got to look after yourself. Top players look after themselves. As I say I don't know actually what's happened but it is something the manager could do without. Put it that way.
"He's got a chance if he screws his head [on]. At the minute it seems to be derailing. That's the reality of it."
Lambert did not rush Grealish into the Villa first-team whilst manager of the club and fans were often frustrated that he was not getting a chance under the former Villa boss.
But perhaps Grealish is the type of young player whose progression needs to be slowed slightly in order to get the best out of his abundant talent.
The Villa lad just needs to sort out his mentality off the pitch if he is to become a star in the Premier League now.