The Vikings' newly-assembled brain trust on offense, coordinator John DeFilippo and senior assistant Todd Downing, hired 10 days apart this month, will help craft the team's approach to finding a starting quarterback.

One device is now at the Vikings' disposal: the franchise tag.

NFL teams, as of Tuesday, have a two-week window to prevent one of their pending free agents from hitting the open market with a one-year contract. The Vikings recently have been proactive in re-signing coveted players the summer before they reach free agency, but they're now in uncharted waters with perhaps the NFL's most unique quarterback situation.

All three experienced quarterbacks — Case Keenum, Sam Bradford and Teddy Bridgewater — are set to become free agents with two caveats: Bridgewater's contract may toll, or roll into 2018, depending on whether he and the NFLPA can prove he was medically able to play before Week 6. And Keenum can be tagged or have his contract extended.

The deadline to apply a franchise or transition tag is 3 p.m. on March 6.

The Vikings have never used the tag, which began in 1993, on a quarterback. Only twice has the organization slapped a one-year tender on a player, and not since Chad Greenway in 2011. Tight end Jim Kleinsasser was tagged in 2003.

Keenum is the most likely candidate, but it would be costly.

A breakout season surprised almost everybody as Keenum parlayed a one-year, $2 million journeyman deal with the Vikings into his eventual career-altering payday this spring. He won 13 games under center, including the franchise's first playoff win since 2009. In his sixth season, he set career highs in completion percentage (67.6), yardage (3,547), touchdowns (22) and passer rating (98.3).

Pinning him down right now would cost $21 million via the transition tag or $23 million for a franchise tag, according to former player agent Joel Corry, who analyzes contracts for CBS Sports.

If the Vikings go the quickest route to keep Keenum with a tag, he'd nearly quadruple his NFL career earnings overnight once he is signed. Teams can rescind tags until they are signed. They would then have until July 16 to negotiate a long-term extension before the upcoming season.

The two sides could work out a long-term deal at any point before Keenum hits the open market March 14. Keenum could command a deal roughly in the three-year, $54 million range with the first year and change guaranteed, according to's Mike Sando. The Vikings and Keenum also will have to consider 31 other potential bidders, who can all legally begin negotiations with the quarterback March 12.