Keenum has never appeared in a postseason game, though he has stood on the sideline for one, as a member of the Texans’ practice squad in 2012, which he affectionately calls his redshirt year. Even if he believed otherwise, the next four seasons foretold little promise that Keenum was capable of shepherding a team to a No. 2 seed and a genuine chance of reaching the Super Bowl in its home stadium, of becoming a reason Minnesota won and not why it didn’t lose.
But here he is, complemented by the N.F.L.’s best scoring defense and a cast of dynamic receiving options, and so are the Vikings.
“I’m going to play like I know how to play,” said Keenum, whom Minnesota signed to a one-year, $2 million contract for this season. “I don’t have to be anybody but myself. Not more conservative or less conservative. Either way, I’m going to be me. That’s all I have to be.”
The eight teams in this round could be divided into distinct groups based on their quarterbacks: those with playoff experience, who just happen to be stars, and those without it, who just happen not to be. Keenum falls into the latter category, but on performance alone he warrants inclusion in the former. His emergence offers an instructional moment for all those teams that do not have a quarterback the caliber of Brady or Drew Brees or Roethlisberger.
A stigma is attached to the term game manager, often applied to quarterbacks asked to execute basic duties spectacularly — make smart throws, think quickly, don’t turn the ball over — but it shouldn’t be. Clutch throws or surgical precision or sharp decision-making might distinguish the best quarterbacks, but by excelling in those areas with regularity they are also, in effect, managing games.
Keenum this season has embodied a more evolved version of the term, minimizing risks while still throwing downfield, thriving in an offense that the coordinator Pat Shurmur adapted to his smaller stature (6 feet 1 inch) and his strengths by moving the pocket and incorporating routes that develop quickly.
The Vikings did not have a single giveaway in the red zone all season, according to the data service Sportradar, and only three other quarterbacks committed as few as eight turnovers while starting as many as 14 games: Brees, Alex Smith and Tyrod Taylor.
Doing what the Vikings have asked, and expected, Keenum stabilized a chaotic quarterback situation. Amid a perfect union of scheme, coordinator and opportunity, he has piloted an offense that not only possessed the ball more than every team except Philadelphia, but also finished those long drives with points, the 10th most in the N.F.L.
“We know that he’s going to get us in the right plays,” receiver Adam Thielen said, “and we know he’s going to find the right guy.”
Those two responsibilities — making appropriate checks at the line of scrimmage and connecting with open receivers — are paramount, and Keenum’s proficiency in those areas has helped land him among special company.
Since the A.F.L.-N.F.L. merger in 1970, only 12 times has a quarterback, as Keenum did, won at least 11 games while throwing for more than 3,500 yards with at least 22 touchdowns and seven or fewer interceptions, per Pro Football Reference. Rodgers and Brady have done so three times each, and the others are a Hall of Famer (Brett Favre), a league M.V.P. (Matt Ryan), an established starter (Derek Carr) and two second-year studs (Jared Goff and Dak Prescott).
As he often is, Keenum is the outlier. Of the four less accomplished starters who play this weekend, only Keenum, the lone undrafted player among Blake Bortles, Nick Foles and Marcus Mariota, wasn’t pegged as a future starter. Two seasons ago, Keenum actually backed up Foles on the Rams.
Asked about the importance of postseason experience, Zimmer said that he would like to have a Hall of Fame quarterback but that he did not think it mattered on game day. That is precisely how you would think the coach whose starter had never played in the playoffs would answer. Keenum lacks the equity stockpiled by Brees, one of the best quarterbacks of this or any generation; it’s one reason Zimmer refrained from anointing him all those times.
The former Giants quarterback Phil Simms articulated the difference by citing an intangible factor, omitting Keenum from the cluster of quarterbacks he calls vampires because, he said, teams must drive a stake through their hearts to beat them.
“If you tell me Tom Brady or Drew Brees gets the football at the end of the game and they get four downs to try to score, I’m betting on those quarterbacks,” Simms, an analyst for the CBS pregame show “The NFL Today,” said in a telephone interview. “I cannot say the same about the other ones.”
In fairness, Keenum has had few opportunities to direct game-winning drives, a function of the offense’s ability to grab leads and the defense’s skill at preserving them, though he does not necessarily have to prove that he can. The Vikings just need Keenum to play well on Sunday.
If he does, if he makes few mistakes and good throws and audibles to the right plays, they will enter a familiar realm. They will get to play again next week.