EDEN PRAIRIE, Minn. -- The man in the ski cap and hoodie was staring through a window at the new purple banner announcing the Minnesota Vikings' division crown. From behind, as he stood in a cafeteria, this average-size Joe could have passed for a food-service worker or a fan who had won a contest for a tour of the team facility. Case Keenum does not look like a quarterback drafted by an NFL team for a damn good reason: He wasn't.

It was a Tuesday, the players' off day following their division-clinching beatdown of the Cincinnati Bengals in mid-December, and an operations crew had just hung the banner in the rafters two minutes earlier. Keenum doesn't believe in off days, so he was the first to see this tribute to the 2017 NFC North champs -- the last of its kind to hang over the indoor practice field in the Minneapolis suburb of Eden Prairie, ID'd on the street corner by a tattered Viking ship encased in snow and ice. The team will pack everything later this winter and move to upgraded digs in Eagan, about 20 miles to the east. Nobody is sure whether Keenum will be along for the ride.

And that's fine and dandy for now. Keenum is not thinking about free agency -- whether he might head to another franchise in a package deal with offensive coordinator Pat Shurmur, or if Minnesota could still prefer the returning Sam Bradford and/or the returned Teddy Bridgewater as its 2018 starter. Short term? Keenum is thinking about beating the New Orleans Saints in Sunday's divisional round matchup at U.S. Bank Stadium. Not-so-short term? Keenum is thinking about becoming the first quarterback in NFL history to lead a team onto its own field with a chance to win the Super Bowl.

"I don't think anybody wants to be sitting here in February and watch somebody else play in it," Keenum said. He retreated a bit from that statement, swearing that the team wasn't looking ahead at a magical shot to earn the franchise's first Super Bowl championship, in its own building, after four losses in the big game and no appearances since the 1976 season. Keenum apologized for the cliché, but said the Vikings were taking it day by day. If there's anyone who knows that NFL life is a day-to-day proposition, it's the quarterback of the NFC's No. 2 seed.

Case Keenum helped the Vikings to their best regular-season record since going 15-1 in 1998. Brace Hemmelgarn/USA TODAY Sports

Keenum's striped gray ski cap was pulled tight over his hair and ears and down to his eyebrows, making him appropriately hard to recognize. He's the improbable leader of a faceless contender, and maybe he represents the look and the formula that will finally deliver these earnest Minnesotans their long, lost ring. The Vikings have had Hall of Fame quarterbacks, quarterbacks who won Super Bowls for other franchises and former top overall draft picks.

But the Vikings have never had a quarterback quite like Casey Austin Keenum -- undrafted, unwanted, un-everything -- who led them to a 13-3 record as the second-most-accurate passer in the league (67.6 percent). Of the quarterbacks starting playoff games this season, Keenum had the best regular-season Total QBR at 69.6 -- second only to the now-injured Carson Wentz's 75.7, and better than Tom Brady's 67.2. Football Outsiders ranked Keenum ahead of Brady as the NFL's top quarterback in 2017 in DVOA, a metric that measures a player's value per snap over an average player at his position.

Not bad for a former Houston Texans practice-squad arm and deposed Los Angeles Rams starter who arrived in March with a 9-15 career record and an upside the Vikings thought was worth a mere one-year deal for a lousy $2 million plus incentives. But this staggering run comes as no surprise to Keenum or to his supporters, who were just as confused when he had just one Division I offer out of high school as they were when he went undrafted in 2012. Keenum is not driven to prove the doubters wrong half as much as he's driven to prove those true believers right.

The believers are multiplying by the week. Keenum has already made himself a lot of money this season, no matter what happens against the Saints on Sunday -- people up and down the Vikings' organization would concede that much, even if some would rather not pay up. An executive from another team who has watched six recent game films of Keenum predicted some franchise will offer him $20 million a year, and that the quarterback would likely leave the Vikings if they offer him $15 million a pop.

"He's playing at a Pro Bowl level," the executive said. "He's put himself in the same conversation as Kirk Cousins. His film is excellent. He's got a live arm, accurate, accurate on three levels, good mobility, tough, smart. I didn't give him a good grade out of college, but his tape this year is outstanding. He's playing like a real quarterback -- a borderline franchise guy -- not a journeyman. You watch six games this year and you say, 'Holy s---, look how good Case Keenum is."

Surprised scouts and coaches have been saying that for years, but the secret to Keenum's success isn't much of a secret at all. He has overcome his modest physical gifts as a 6-foot-1 quarterback with a fearless approach to competition and life that was clear long before he started wowing Wylie High School football fans under Friday night lights in Abilene, Texas. In fact, Keenum didn't first declare his bold spirit on a football field, but in the middle of a Costa Rican jungle.

"You want stories, right?" Steve Keenum asked over the phone. "Let me give you one."

It was Christmastime 1999, and the Keenums were heavily involved in the Fellowship of Christian Athletes. Steve and his wife, Susan -- former athletes at McMurry University in Abilene, where Steve was later the head football coach -- decided to spend the holidays with family members who were doing missionary work in Costa Rica. They were on a boat ride down the Colorado River, a tributary near the Nicaraguan border, when an 11-year-old Case decided to kick the adventure into a higher gear as he watched his uncle pull his older cousin on a boogie board behind the boat.

"My son looked at me and asked, 'Can I do that?'" Steve recalled.

Steve had seen some crocodiles on the banks of the river. He also knew the flow of the river could be unpredictable and potentially dangerous to a boy putting a higher premium on fun than safety. "But I told my wife that I'm going to let him do it," Steve said. "I didn't want him to be afraid of anything, and he did it. ... If he wanted to try something that involved risk, I wanted him to feel he could do it and not shy away from it."

Case Keenum always preferred to lead with his chin. As an eighth-grader, he was running the anchor leg on a Wylie relay team in a race that would determine the winner of the district meet.

"I remember getting the baton in third or fourth place, and I was going to catch the guy in front of me no matter what," Keenum said. "I was being ultracompetitive because that's just who I am."

Watching that day was Hugh Sandifer, then the head football coach of the varsity team at Wylie. He knew about Keenum, and figured someday the middle schooler would start for him. But Sandifer had no idea what he'd be getting until Keenum dove face-first across the finish line to win the district title for his team at the expense of his skinned-up elbows and knees.

"He just flat dove like Superman," Sandifer said. "It was insane. You just don't see people dive at the finish line. I think we knew then that he was going to be special."

Football would be his game, and his right arm would be his weapon of choice. Steve had made his living coaching high school and small college ball, and he helped strengthen that right arm when he was working at McMurry, where a young Case would follow his dad from the locker room to the weight room to the field wanting to be a ballboy. Steve had a rule for his son: You can't be a ballboy until you can throw a college-size ball from the sideline to the hash mark where the officials usually stood. Case kept practicing that throw, and at age 10, his arm proved reliable enough for the job.

Keenum started for Sandifer's varsity team as a sophomore and led the Bulldogs to the Class 3A Division I state title game as a junior in 2004. Down a touchdown in the fourth quarter to a favored 14-0 Cuero High School, Keenum found his tight end, Josh Archer, for the tying score, then made the signature play of his Wylie career: On third-and-11 at the Cuero 48-yard line with less than a minute to play, Keenum escaped pressure and ran 39 yards to set up the game-winning field goal. "If I had been able to hold my block better, he would've made it all the way in," Archer said. Wylie football had never won a state title until Keenum showed up, and hasn't won another since.

Case Keenum wore purple and gold at Wylie before donning the same colors for the Vikings. Courtesy Tim Nelson

Keenum lost his chance at a second championship as a senior while playing his final game in Texas Stadium, which was still home to the Dallas Cowboys. He threw for a touchdown and ran for two more in the quarterfinals, including a 38-yarder punctuated by a prototypical Keenum dive and, unfortunately, an injured right shoulder. Sandifer wanted to take Keenum out of the game, but the quarterback wouldn't allow it. Down 25-22 on the last possession, Keenum heaved a 50-yard pass into the end zone that was dropped. They learned after that Keenum had unloaded the pass with a separated shoulder.

The big-time schools still didn't want him. Sandifer has been at Wylie 39 years (32 as head coach), and Keenum's is a recruiting mystery the coach still can't solve. Sandifer told coaches all about Keenum's crazy numbers and relentless heart, but they couldn't get past the fact Keenum was only 6-1.

"They kept talking about height and arm strength, and some of them would bring up speed," Sandifer said. "My response was always: 'I don't know what the 40 times are of the guys chasing him, but he's always a half-step ahead of them.'" Art Briles of the University of Houston was the only Division I coach to offer Keenum a full ride.

Kevin Sumlin came in after Briles left for Baylor and installed a freewheeling, no-huddling offense that made Keenum the point guard on a perpetual fast break. He loved it -- he had complete control of the offense and the authority to check to whatever he wanted, whenever he wanted. He tore up his knee in what would have been his senior season, then returned on a redshirt in 2011 to throw 48 touchdown passes and just five interceptions while clearing 5,600 yards for the second time. Houston went 12-1, beat Penn State in a bowl game and then waited for Keenum, the most prolific passer in major college history, to get drafted. He finished his career with a record 155 touchdown passes and 19,217 passing yards -- more than 2,000 yards better than the second-place quarterback on the FBS all-time list, Hawaii's Timmy Chang.

Keenum figured some team might pick him in the middle or late rounds. He didn't arrange for a lavish party. He watched the later part of the draft at a cousin's house, and wasn't terribly disappointed when his name wasn't called. Like his parents and two sisters, Keenum was active in the Fellowship of Christian Athletes and thought God had a plan for him. "You take a look back at some tough parts of your life," Keenum said, "just bad things that have happened, they tend to build your character and make you who you are."

Then-Texans coach Gary Kubiak liked Keenum, signed him and gave him a chance to make it in the league. Keenum had so much to learn about running a conventional NFL offense, getting under center and playing with an actual tight end. He got his big break in 2013 when Matt Schaub coughed up a dizzying series of pick-sixes, and Keenum responded by throwing for seven touchdowns and 822 yards without an interception in his first three games. Problem was, Houston failed to win any of those games. Keenum's production fell off, and before he knew it, he had lost his first eight NFL starts.

"It affected me," he said. "It didn't stop me. ... It beat me down physically, mentally. I wasn't used to losing, and I took a lot of that on myself. I think that's why I play quarterback. You get the ball in your hands and you make decisions every play. And to not be successful like that was really hard, really frustrating. And it took some time to learn from that."

Keenum lives in a Minneapolis suburb with his wife, Kimberly, who grew up with Case in Abilene. They attended the same church, and Susan Keenum was Kimberly's fifth-grade phys ed teacher. They saw each other at track meets and FCA events, and one day in his junior year of high school, Case asked the senior, Kimberly, to get a snow cone. They've been together ever since.

But the 0-8 start to Keenum's career tested what had been a charmed existence. The quarterback was bringing his workplace struggles home with him. "I was burning the candle at both ends that year," Case said. "I would go in early and I would stay late, and all I thought about was football. You can't win like that. You can't live like that. My wife is incredible and we have a great relationship, but our relationship suffered. Not between us, but just because of the stress. You're not a healthy person when you're worrying that much. So that was one of the things I learned. This game, you can put everything you can into it, but that's all you can put into it. If you try to do more, sometimes it ends up being less."

Keenum was waived by the Texans, signed and waived by the Rams and then re-signed by Houston off the Rams' practice squad. He claimed his first career victories against Baltimore and Jacksonville at the end of the 2014 season, then was traded back to the Rams for a seventh-round pick in 2015. He suffered a concussion against the Ravens that season that exposed the flaws of the league's protocol when he was never removed from the field; he recovered to win three of his final four games and lock down the starting job for the franchise's first season back in Los Angeles in 2016. He knew he was keeping the position warm until Jared Goff was ready to go. And after nine games (four of them victories), Jeff Fisher gave the No. 1 overall pick the ball.

Minnesota knew Keenum could play a little bit -- he did complete a Rams-record 19 consecutive passes, throwing for 321 yards and three touchdowns in a shootout loss with Detroit's Matthew Stafford. But Minnesota had no idea Keenum would become one of the league's more valuable players after starting the season without Bridgewater, then losing Bradford in Week 2. The Vikings had no idea that the obstacles their new quarterback had to overcome, in Keenum's words, "made me into a tough SOB."

His toughness was never more evident than on a 22-yard touchdown pass to Kyle Rudolph on Thanksgiving Day. From the shotgun, Keenum saw Lions safety Miles Killebrew move up to the left side of the defense before the snap. Keenum adjusted his protection to account for the blitz, took the snap and then saw Killebrew bearing down on him with no impediment in sight. Keenum could have scrambled, folded like a tent or thrown the ball away. Instead, he stood firm and waited for Rudolph to get open on his corner route, then delivered a perfect pass over the top while Killebrew crashed into his rib cage. As Keenum fell to the turf, he smacked into a lineman to his rear. He didn't feel any pain amid the delirium of the moment. "But I was as sore as can be the next day," he said.

Vikings coach Mike Zimmer didn't need to see that play to form an opinion on Keenum. Before Minnesota even played Detroit, Zimmer offered an old-school scouting report: "The thing I like most about Case is he's got big balls."

Case Keenum's 67.6 completion percentage was second only to Drew Brees in the regular season. Geoff Burke/USA TODAY Sports

Keenum was strong against the blitz all year, and strong outside the pocket. Yet the most profound impression he made on his teammates involved the hours he kept and the passion he showed. It's common for quarterbacks to be first-one-in, last-one-out types; it's all but written into the job description. But they say Keenum takes that to a new level. Quarterbacks coach Kevin Stefanski normally shares his first cup of coffee with Keenum around 6 in the morning, and the two of them let the caffeine put the daily game plan into focus. Stefanski has been around a lot of grinders in his dozen years with the Vikings, but Keenum is in a league of his own. "His self-motivation is off the charts," Stefanski said. "He's obsessed with the process."

Adam Thielen might be the teammate most qualified to define Keenum's hunger. As an undrafted Division II player out of Minnesota State-Mankato, Thielen had an even tougher road to navigate to the NFL than Keenum's. The Pro Bowl receiver doesn't discount the possibility that their seemingly symbiotic bond is rooted in their shared backstory, though he guesses he has a better explanation for their success as first-time teammates.

"I think honestly what makes our connection good is we don't really care what people think about us," Thielen said. "We just want to go out there and help the team win."

Thielen moved the conversation back to Keenum's work ethic. "He's not just showing up at 6 a.m. just to be here. He's got a plan. He knows the defense before we play them, and he knows the game plan better than anyone I've ever been around. ... Maybe even better than some of the coaches."

It has grown increasingly difficult to discredit Keenum. A division champ at 29, he has moved beyond the phase of his career his old man described as, "Would you hurry up and fail so we can turn to someone else?" He's going to be a no-questions-asked first-stringer somewhere in 2018, and he's going to get paid. The exec who thought Keenum would get $20 million a year said he would still slightly prefer Cousins running his team, but all things being equal, he would take Keenum over Eli Manning if the New York Giants made their longtime starter available.

Until further notice, Keenum and the state of Minnesota are madly in love. Keenum and his wife, Kimberly, claim to have All-Pro neighbors. "Minnesota nice is a real thing," he said. Those neighbors have shoveled the couple's driveway and sidewalk to prevent the quarterback from potentially slipping on the ice. "Let's be honest," Kimberly said, "these Texans don't know what to do with all of this snow!"

The couple has similar support back home, where Keenum's former Wylie teammates get together to watch the quarterback who led them to a championship as teenagers. They say his humility makes it easy to root for him. They watch him escape when the Vikings' pocket collapses, and it takes them back to those Friday night lights in Texas when Keenum would escape the same way in Wylie colors. Sandifer used to joke that he ran a Monday Night Football offense -- whatever he saw and liked on MNF, that's what he put in for the next game. He was in the crowd for his first Vikings game when his former quarterback, now wearing lucky No. 7, ran a more sophisticated attack to beat Cincinnati and clinch the NFC North.

It's a hell of a story with a credible chance to get much better. Can Keenum become the next Kurt Warner, another undrafted star to win it all? Can he actually become the first Super Bowl champ crowned in his team's own building?

"It would be a fairy tale kind of thing," his father said.

Even if that fairy tale ends on the first Sunday in February, in Super Bowl LII, before Keenum potentially leaves to play for another team. It's hard to believe this blissful marriage of player and market will be reduced to a one-and-done by money, but the NFL is a business, and oftentimes a cold one.

Keenum wants to win a title now, and worry about his future employment later. He said the Vikings are "confident [they] can beat everybody," and there isn't a man in his locker room who would argue that the quarterback hasn't inspired that faith. He arrived in Minnesota with a losing record and a losing contract, and he made a head-first dive into a brand-new day.

Anything can happen in the playoffs, and nothing is guaranteed in Minneapolis -- or in free agency. But you can take this to the U.S. Bank: If the Vikings fail, it won't be because their quarterback was afraid to succeed.