Gerrard, who announced his England retirement on Monday, turned 34 in May, but former striker Rush thinks that the Reds skipper can still play on for a number of seasons.
FourFourTwo quotes him as saying: "It's how well the manager coaches him really. I think there's still another two years left in Steven Gerrard.
"It's not just about physically, I think being in the dressing room before that, motivating people, getting people going and that's what he's all about. He's a leader and we need those leaders.
"Even if they're not producing the best on the pitch we need them in there. Without a doubt if the manager treats him well he's got another two years left in him."