Sam Bradford (knee) a game-time decision for Vikings

The health of Sam Bradford's surgically repaired knee is something the Minnesota Vikings are monitoring, and there's a chance it could sideline him for Sunday's game against the Pittsburgh Steelers.

Bradford, fresh off an impressive performance in the Vikings' season-opening win over the New Orleans Saints, is listed as questionable for Sunday after being limited in practice all week because of a knee injury. Despite the designation, Vikings coach Mike Zimmer told reporters Friday he anticipates Bradford will start this weekend.

However, NFL Network Insider Ian Rapoport reported Sunday morning that Bradford will be a game-time decision after he takes part in a pregame workout. If he doesn't play, Case Keenum will get the start.

Rapoport provided some clarity on Bradford's situation during NFL Total Access on Friday:

"It doesn't sound like they're too concerned with Sam Bradford," Rapoport reported. "He's a little banged up. Had an MRI, had some tests. It did not reveal any structural damage, but the problem is he's had a lot of structural damage on that knee, so the actually MRI and what they found may be hard to decipher. Of course, he's had two [torn] ACLs. But they do think Sam Bradford is going to be on the field and playing, this just might be something he needs to kind of work with and deal with some maintenance on over the next couple weeks."

ESPN first reported Bradford underwent an MRI.

Bradford's left knee has the injury history of a grizzled NFL veteran despite its 29 years thanks to a pair of torn ACLs. It's a big part of the scouting dossier on the seventh-year pro, and it makes sense that the Vikings would play it safe with Bradford.

Still, it's hard to bench a guy coming off a 346-yard, three-touchdown performance unless it's absolutely necessary. It'll be up to the Vikings' offensive line, which tried to bury its 2016 demons with an impressive game versus the Saints, to ultimately give the protection Bradford needs to perform and stay healthy against a robust Pittsburgh pass rush.

UPDATE: Bradford has been ruled out for Sunday's game.