Source: Vikings signing QB Case Keenum as Sam Bradford's backup

The Vikings will sign quarterback Case Keenum, a league source confirmed to the Star Tribune.

Keenum, 29, started a career-high nine games last season for the Los Angeles Rams and will provide a healthy backup presence for the Vikings behind starter Sam Bradford as Teddy Bridgewater continues to rehab from severe left knee injuries. ESPN reported that Keenum's one-year contract is worth $2 million with more available through incentives.

Vikings coach Mike Zimmer hinted at the move earlier this week during the NFL owners' meetings while addressing questions about Bridgewater's uncertain playing future. Zimmer was asked his comfort level with unproven third-year passer Taylor Heinicke as the team's only other quarterback under contract.

"I think we're going to get some things done there," Zimmer said.

And they did.

Keenum (6-1, 205 pounds) has started games in four of his five NFL seasons, with a 9-15 record. He completed 60.9 percent of his passes for 2,201 yards, nine touchdowns and 11 interceptions last season for the Rams. Keenum started L.A.'s first nine games before the team handed the reins to first-overall pick Jared Goff.

Keenum went undrafted in 2012 out of Houston, where he set all-time FBS records in passing yards (19,217) and passing touchdowns (155) for the Cougars.

Former Vikings backup Shaun Hill, who appeared in three games and started one last season, became a free agent this offseason and remains unsigned. Heinicke, who hasn't thrown a pass in the regular season, was the other option alongside Bradford and Bridgewater.

Bridgewater's ongoing recovery from a dislocated knee and multiple torn ligaments does not have a set timetable. So the Vikings cannot bank on his return in 2017 and will press forward with a Bradford-Keenum pecking order into this summer.

"There really is no other plan [for the future at quarterback] until Teddy gets healthy," Zimmer said. "When he gets healthy, we'll worry about it. We don't know when it's going to be. If he comes in tomorrow and is 100 percent, which he won't, but if he did, then we'd have to adjust things. But right now we don't know when he's going to be ready."

Bradford took a pounding at times last season behind a beleaguered offensive line.

The Vikings have tried to shore up the line by signing tackles Mike Remmers and Riley Reiff, and getting one of the league's better pass-protecting running backs in Latavius Murray. Still, they now have added security for Bradford in Keenum.