Matt Hasselbeck and Field Yates react to Eli Manning's belief that he can play another four years. (1:30)

EAST RUTHERFORD, N.J. -- Tom Brady has said he wants to play into his mid-to-late 40s. The only quarterback to beat him in a Super Bowl, Eli Manning, said Tuesday he thinks he can at least make it to 40.

"Yeah, I think sitting here right now, I think I can play another four years," the 36-year-old quarterback of the New York Giants told ESPN.

"That's the way the body feels. ... Again with football, you don't know what's going to be the difference, how you're going to feel next year. And right now I still have the same enthusiasm and I'm working hard and I like doing the training and watching film and doing everything ... I have to do to prepare for it. So I don't see it slowing down. I think until the time comes or that changes, I'm going to keep going as hard as I can."

Manning is under contract through the 2019 season; he would turn 40 at the end of the 2020 season.

The Giants have talked about limiting his workload this summer and keeping him on a "pitch count," and they've acknowledged that Davis Webb, their third-round pick out of California, could end up as Manning's replacement in the not-too-distant future.

In January, Giants general manager Jerry Reese said the 14-year veteran and two-time Super Bowl champ is "probably on the back nine" of his career.

Manning has been one of the more durable quarterbacks in NFL history. He is scheduled to start his 200th consecutive regular-season game in the season opener at the Dallas Cowboys on Sept. 10.