The safety, who joined the AFC North side last month, is yet to play a full NFL season since entering the league four seasons ago with the St Louis Rams, and has missed seven games through injury in the last two seasons.
The 25-year-old told the team's website: "I'm just making sure I eat right. And with my hamstring, I'm doing whatever I can to stay out there on the field, just doing extra treatment and things for my legs and making sure I'm in the best shape come off-season workouts.
"I feel like I'm interchangeable. Whatever they want me to do, whether it's special teams, defense, anything position-wise on defense, I feel like I'm able to excel in it. I feel like they'll get an overall safety."
Stewart featured in 13 games for the Rams last season, making 30 tackles and a forced fumble.