Several major questions related to the 2018 season have been staring at the Vikings for months, but always with the caveat that they would be dealt with when the team's surprisingly successful season finally ended.

Well, that happened Sunday. And now perhaps the most important of those questions — who will be the starting quarterback in 2018 for a team that went 13-3 during the regular season and made it within a game of playing a Super Bowl in its home stadium — is at the forefront of an interesting offseason.

Teddy Bridgewater started every game in 2015 for a Vikings team that made the playoffs. Sam Bradford started 15 in 2016. Case Keenum started 16, including two playoff games, for Minnesota in 2017.

All three were on the roster this year, and all three are free agents.

"I have an inkling that all those guys are going to be starting quarterbacks in this league for someone and they're going to win a lot of games," Vikings wide receiver Adam Thielen said Monday. "They're that kind of character guys and that kind of players."

So now what?

Multiple national reports Sunday indicated the most likely scenario is that the Vikings will use the franchise tag on Keenum, which would be a one-year commitment at more than $20 million. The Vikings can use that tag on one impending free agent during a 15-day window starting Feb. 20.

"I really haven't thought too much about it," Keenum said of his contract status, when asked by reporters Monday during locker room cleanout day back in the Twin Cities. "I love this team. I love these guys. Love the coaching staff. I love this whole organization. … The culture they have around here is just awesome. Minnesota itself, the people here have been great."

That said, Keenum said he plans to go somewhere warm and let the process play out. Putting the franchise tag on Keenum would seem to be an easy solution to the Vikings' conundrum. That said, it's hard to imagine the situation being more unusual or complicated.

To recap: The Vikings acquired Bradford in 2016 after Bridgewater's knee injury late in the preseason. At the time, Bradford had two years left on his contract.

Bradford stayed healthy in 2016 and entered 2017 as the starter, with Keenum signed to a one-year, $2 million deal while Bridgewater continued his recovery. Bradford was injured during a wonderful Week 1 performance against the Saints, and Keenum ended up playing all but two quarters for the rest of the season.

Bridgewater returned to the active roster in early November. When Bridgewater came back to the active roster, Bradford went on injured reserve. It was speculated that Bridgewater could replace Keenum at some point down the stretch, but Keenum's strong play kept Bridgewater on the bench with the exception a brief appearance late in a blowout win over Cincinnati.

Bradford was activated before the Vikings' first playoff game and served as the No. 2 quarterback behind Keenum for both postseason games, with Bridgewater inactive for both.

"This year I think my biggest test was my character," Bridgewater said Monday. "In a perfect world, I would have loved to have been dressing, but I understand decisions are made to give this team the best chance to win. I understand that and I'm a pro. I know what it takes. It happened, and I dealt with it."

Bridgewater said he didn't read too much into his demotion to No. 3 when it comes to interpreting the Vikings' long-term plans, but he said he's "definitely, without a question" worthy of being a starting quarterback for someone in 2018.

Bridgewater and Bradford have injury histories, but the Vikings have also heavily invested time, draft picks and money in both. Keenum helped carry the team to a 13-3 record, but his play in the NFC title game and his overall history are in question.

Don't forget, too, there is a fourth quarterback possibly in the mix in some way: Kyle Sloter, the undrafted rookie free agent whom the Vikings paid a premium to sign to their practice squad and who served as the No. 2 quarterback behind Keenum for several weeks while both Bradford and Bridgewater remained out.

Will the Vikings put the franchise tag on Keenum, paying a premium for one year without having to commit long-term? Do they hesitate given that offensive coordinator Pat Shurmur, credited for helping Keenum excel this year, is slated to become the Giants head coach?

Would they rather turn back to Bridgewater, who because of his injury and Keenum's production has barely seen game action for two full seasons? Would they risk signing Bradford — who did not address the media Monday — and hope he stays healthy?

Will they eschew all three and make a play for another quarterback in free agency? Someone like Washington's Kirk Cousins could be a fit on the open market, and the Vikings will have cap space to make a big move if the opportunity presents itself.

"I'm sure those guys (in the front office) are going to do the best they can to give us the best chance of winning with the decision they make," running back Latavius Murray said.

As of now, though, it remains a situation with more interesting questions than obvious answers.