EDEN PRAIRIE, Minn. -- Not once this season has Case Keenum gone into a week of game prep as the announced starter.

Unlike in coaching, the "interim" tag is not as widely used with players. Effectively, Keenum has been the interim starter for the Minnesota Vikings in Sam Bradford's absence. The uncertainty caused by Bradford's knee injury put one giant question mark over the entire position group early on.

Coach Mike Zimmer has reiterated that if Bradford is healthy enough to play, the job is his. In all but one game, he hasn't been, but the Vikings haven't altered their course on how to manage the position between starters and backups.

The uncertainty Keenum faces on a week-to-week -- even daily -- basis is his new normal.

Even after leading Minnesota to three wins, Keenum still enters each week not fully knowing whether he'll take snaps with the first-team offense or slide into the backup role he was brought in for during the offseason. Even when it appeared relatively obvious that Bradford would not be ready to go (such as when he reinjured his left knee in Chicag0), Keenum has never officially been deemed the starter at the beginning of a week.

It's why he has repeatedly said he approaches each week as if he's going to start. That way the amount of work he gets in practice doesn't throw off his ability to get into a groove, and he doesn't subject himself to a rollercoaster of uncertainty.

"It's just trying to do everything you possibly can the same as if you are getting the reps," Keenum said. "I stand behind the play and get the same reps. I visualize the same reps. I go through the plan. I prepare to go practice as if I'm getting the same reps."

That mindset is apparent to his teammates, who haven't seen Keenum change his approach regardless of what his role will be in a given week.

"He knows the game plan better, probably, than some of the coaches because he's in there studying every morning," Adam Thielen said. "He's the first truck in the parking lot. I know that's cliché but it's the truth. He gives me crap when I get here before him because he doesn't like that too much. He wants to win. He doesn't really care how it's done, he doesn't really care who's playing. He's a competitive guy so when he's out there he wants to do whatever it takes to win."

Bradford was absent for a fourth straight practice when the Vikings began preparations for the Ravens. If he's unable to return this week, Keenum will start his fifth game this season.

After a 14-month hiatus, Teddy Bridgewater returned to practice on Wednesday. Minnesota will now have to find the balance between getting Keenum ready to lead the offense while preparing Bridgewater to see if he can play this season.

The way Keenum is handling that situation, which isn't a question the Vikings need to answer in the short term, is a positive attribute for the coaching staff. They never have to worry that he'll be ready to go when he's needed.

"Case is Case," Zimmer said. "He just does what he has to do to get ready. I get it, the fans and the media and everybody is so excited about Teddy being back. He's still got a ways to go. So, we need to just remember that. That he's still working, a work in progress. If and when the time comes, we'll get him in there and we'll go. For right now, it's business as usual."

The life of a backup quarterback is rooted in ambiguity. These players are stuck with the blame if they go in and can't perform and don't get the credit when the going is good and they're on the bench.

Keenum knows his role in this scenario and where he fits into the mix. This temporary situation has been drawn out throughout the first half of the season, but his attitude hasn't changed.

"I try to make every offense that I'm in my offense. Whether it's just knowing the intricacies of every little parts of routes, protections, run game checks … knowing guys and how they react, how they play, what they want to hear. Whether it's operating in the huddle, talking to the coaches. No matter what offense I'm in, I'm continually trying to master it. I always use the mindset -- never feel like I've arrived. I'm always striving for more. That's my mindset. I want more."