That's a big "if" for a player who has battled leg and foot injuries since entering the league as the rare power back capable of blazing a sub-4.50 40-yard dash.
It's not just the two touchdown runs versus the Chiefs that have Rivera excited. On a 15-yard scamper, Stewart also showed an extra burst that was noticeably missing from his repertoire last year.
"When he does get back out there you realize why he is so special and why you keep giving him chances to come back," center Ryan Kalil said, via the Associated Press. "I've played so many games with him and watched so much film, you see a guy that people want to keep fighting and fighting for. I think he is such a huge part of our running game and it's great to have him out there."
A healthy Stewart isn't just better than a 31-year-old DeAngelo Williams. He's one of the most talented running backs in the league.
Unfortunately, he's also one of the NFL's most unreliable skill position stars.