Aston Villa skipper Grealish inspired his side to a shock 2-1 FA Cup last-four win over Rodgers' Liverpool in 2015.
It was the last time the Foxes manager has suffered a domestic cup defeat and Leicester host Villa in a Carabao Cup semi-final first leg on Wednesday.
He said: "To be fair to Jack, you have seen the maturity in him and it was difficult when he broke through because he was playing for his hometown club, the club he loves, so there was real emotion around it.
"He has broken in, lots of people are hanging around him and everything else but after they got relegated he took on a greater responsibility, showed a leadership role with the club and has helped bring them back up.
"With Dean (Smith) who has the connection to Villa, he knows what it means to work for the club.
"He has matured a lot since the time he was a talent and looks like he has fully developed physically and is a wonderful player."