Case Keenum already is a veteran at slogging through the NFL's career quicksand.

He made 14 consecutive starts for the Rams, during which the franchise moved from St. Louis to Los Angeles, then made Keenum's future with the team clear by drafting Jared Goff in 2016 with the No. 1 overall pick.

"I learned a lot, man," Keenum said Tuesday in a conference call with Twin Cities media. "Specifically in my case, you know, I'd say the one thing I tried to do — and I feel like I did a pretty good job — was just kind of keeping my head down and keep moving forward. … not worrying about too many externals or what other people are thinking or doing."

And that wasn't even the beginning of tough times for the Vikings' new backup quarterback.

Keenum, undrafted in 2012 before signing with the Texans, has already been traded, waived twice and signed off a practice squad. After becoming the NCAA career leader in passing yards and touchdowns at the University of Houston, Keenum continues an NFL journeyman career in Minnesota after bouncing between Houston, St. Louis and Los Angeles the past five seasons. He has started at least two games in each of the past four seasons.

All those ups and downs could serve him well at Winter Park, where he'll be one injury away from starting again.

Keenum, who signed a one-year contract with the Vikings, enters another evolving quarterback situation. He's next in line behind Sam Bradford while the other Vikings starter, Teddy Bridgewater, continues indefinite rehab from severe knee injuries suffered last summer.

Keenum and Bradford are at least familiar with each other, having met in St. Louis meeting rooms in 2014 when Bradford was rehabbing a torn ACL. Bradford has started 29 games for the Eagles and Vikings in the two seasons since. Third-year passer Taylor Heinicke, a promising talent, also will be calling signals for the Vikings. Veteran Shaun Hill was let go in free agency.

"I'm ready to come in and compete," Keenum said. "I'm going to come in and learn the offense as quickly as I can and focus on trying to make this team better."

Easing his latest transition will be knowledge of the Vikings' offensive approach under coordinator Pat Shurmur. Keenum, 29, navigated similar passing philosophies with the Texans and Rams, leaving the latter with 13 touchdowns, 12 interceptions and a 7-7 record as a starter.

"I've got a similar background, I guess you could call it, [with] what the core of the offense is," Keenum said. "Obviously different terminology and different things they're trying to do specifically with different weapons they have, but I've got a lot of familiarity with it. A lot of it I feel like I'm speaking the same language in certain areas as the coaches."

Keenum saw his longest run as an NFL starter end when the Rams handed the reins over to Goff in November following a 1-4 skid in the standings.

A better defined quarterback situation awaits him with the Vikings, but he's experienced in how quickly circumstances change. So is the Vikings organization, a franchise that has started six quarterbacks in the past four seasons.

"Obviously didn't win all the games I would've liked, but I've learned from it and I've grown from it," Keenum said. "I'm excited about what it's taught me and where my career is going to go now."