Coach Mike Zimmer described the Vikings’ top draft pick, center Garrett Bradbury, as “aggressive,” “brilliant” and “businesslike” after Tuesday’s opening training camp walk-through, which was limited to rookies and quarterbacks.

Bradbury, who turned 24 last month before taking an NFL snap, proved his business approach this month. The rookie was one of 40-plus NFL offensive linemen who gathered to watch film, share notes and talk shop at a Texas training facility outside the Dallas Cowboys’ headquarters.

VideoVideo (01:46): Minnesota Vikings head coach Mike Zimmer talked to the press on the first day of training camp.

Bradbury’s three-day crash course started with an invite from renowned offensive line trainer Duke Manyweather, who coordinated the second annual O-line summit. He stayed with Vikings teammate Rashod Hill, who lives in Dallas, and learned from the group including All-Pro Eagles tackle Lane Johnson, Broncos guard Ronald Leary and Buccaneers center Ryan Jensen.

“I figured I had a few weeks off,” Bradbury said. “I thought it’d be great.”

They studied tape of All-Pro pass rushers from the Broncos’ Von Miller to the Rams’ Aaron Donald, with veterans sharing tips on how to minimize damage by elite defenders. Few topics were off limits, according to Bradbury.

“I know it’s kind of highlighted that we talked through different defensive players, but I think more than that, Duke just kind of opened it up,” Bradbury said. “ ‘Hey, what are some recovery techniques? What are some off-the-field things that y’all do mentally, physically?’ Just hearing from guys that have done this for seven, eight, nine years was huge for me.”

Whether tips focused on defenders or crowd noise or confidence issues, Bradbury said he was all ears around NFL elders.

“I was just notebook open, pen to paper the whole time,” Bradbury said.

Cleared for takeoff

Rookie long snapper Austin Cutting said getting to Tuesday’s opening training camp practice was a hurdle. A prolonged process ended last week when Cutting was assigned to the Air Force Academy’s recruitment program, allowing him to be stationed in Minnesota and pursue his NFL career alongside his two-year service requirement.

Cutting signed his rookie contract Monday, ending his uncertainty about whether the Air Force and the Vikings would work out something before Tuesday. Now the seventh-round pick is cleared to compete with incumbent Kevin McDermott for the long snapper job.

“It was stressful because it was nothing that I could control, yet was still something that I had to keep up with and monitor,” Cutting said. “Just getting here for training camp was a big thing.”

Room in the backfield

General Manager Rick Spielman classified the release of running back Roc Thomas, who was suspended three games by the NFL after a felony charge of marijuana possession in Dakota County, as a “football decision.” The removal of Thomas, who cleared waivers Tuesday and is now a free agent, leaves the Vikings with five running backs for training camp.

The Vikings kept five running backs on last year’s 53-man roster. So the current backfield reserves, from rookie Alexander Mattison to second-year Mike Boone, have room to jockey for playing time.

“I hope I can come in and contribute any way I can,” Mattison said. “Be a physical back on the offensive side.”

QB battle approaching

Spielman declared the backup quarterback job open between three candidates in veterans Sean Mannion and Kyle Sloter and rookie Jake Browning. The trio has only Mannion’s 53 career NFL passes to their names, leaving Vikings coaches open to Sloter — in his third NFL season — or Browning — the rookie out of Washington — winning the job to back up Kirk Cousins.

Cuts by other NFL teams or a trade could also present options for the Vikings.

“The quarterback position will be critical behind Kirk between the three we have back,” Spielman said. “That will be a fun competition to watch when we get going.”