The Tennessee Titans quarterback is entering his third season in the league, having led the side to second- and third-placed finishes in the AFC South in his first two years.
The wide receiver told TitanInsider: "I was there in Ben's second year, and right away you kind of understood that, even in his second year, he was gonna be a good quarterback, a guy that could make plays.
"That's the same thing with Jake. He's a guy who can make plays. I tell everybody all the time, this is football, and it's a gladiator sport, but it's not a dumb man's sport."
Roethlisberger has won two Super Bowls with the Steelers.