MANKATO – Among the motley crew of Vikings who kicked off training camp Monday was safety Antone Exum, the oft-injured converted cornerback who has found a way to stick around on the roster for three-plus seasons.

Exum was permitted to practice Monday because a knee injury sidelined him during the final phase of spring workouts. It was the latest medical setback for Exum, and based on his explanation of it, this one was probably the flukiest.

During the second practice of spring workouts, which was not open to media, he was "just standing still" on the field when a teammate crashed into him.

"Guys were just being aggressive and somebody got thrown into my [leg]," said Exum, who admitted he couldn't help but think, "Here we go again."

Exum's NFL career has stalled in part because of these untimely injuries.

In 2015, he got his first two NFL starts but was placed on injured reserve after injuring his ribs and shoulder during a collision. He suffered a leg injury last preseason, and although he returned to full health within weeks of getting hurt, he was placed on IR again as the Vikings trimmed their roster.

"It's really been like freak accidentally injuries, so it's really frustrating," he said. "You just have to keep pushing forward. I'm not going to quit or anything."

Back on the field for the start of camp, the 26-year-old must convince the Vikings he is worth keeping around as one of their two or three backup safeties behind Harrison Smith, a Pro Bowler, and Andrew Sendejo. His competitors are youngsters Anthony Harris, Jayron Kearse and seventh-rounder Jack Tocho.

Asked if he is feeling more pressure than ever while trying to hang onto to his roster spot, Exum, a sixth-round draft pick in 2014, bluntly replied, "No."

Cook doing well

With Latavius Murray on the mend and Jerick McKinnon not scheduled to arrive until Wednesday, second-round pick Dalvin Cook was first in line for reps Monday. So far, through spring workouts and the start of training camp, offensive coordinator Pat Shurmur likes what he has seen from Cook in terms of his attitude and aptitude.

"I think he tries to make the most of every rep he gets. You see him do a lot of things really well, and if he does make a mistake he's able to correct it and move on. That's another sign of being a pro," he said. "I think he's going to have a bright future."

Shurmur said Cook will also benefit from coming from "a pretty advanced offensive system at Florida State" as he looks to seize a significant role.

"You saw principles of zone running, gap running, and pass protection where he was involved. He was also involved in route running," Shurmur said. "He has a pretty good foundation of what we're going to ask him to do, and I think that helps him."

Bridgewater likely out

In addition to running back Murray, who is still recovering from March surgery to repair a torn ligament in his right ankle, the Vikings also placed rookie linebacker Shaan Washington on the physically unable to perform list. They are expected to place quarterback Teddy Bridgewater on the PUP list as well, but don't have to until Thursday, the day of the first full-squad practice.

The team put defensive tackle Sharrif Floyd, still sidelined after suffering nerve damage during knee surgery last September, on the non-football injury list.

Vikings sign tackle

The team on Monday signed 6-foot-7, 305-pound offensive tackle Arturo Uzdavinis, a second-year pro who previously spent time with Houston, Chicago, Jacksonville and Detroit but has yet to appear in a regular season game.

Uzdavinis was on the field Monday morning, which was a good thing considering they have only four other offensive linemen available to practice while the Vikings wait for their veterans to report on Wednesday.

With the Vikings starting training camp early this year, only rookies, a trio of quarterbacks and a few select veterans suited up for Monday's practice.