MANKATO – If not for the imposing shadow his 6-5 frame casts on the practice field, spotting Vikings top pick Anthony Barr before the snap would be like playing a game of "Where's Waldo?"

On Friday, Barr lined up across from left tackle Matt Kalil and rushed off the edge on one play. On the next, Barr stood behind the left defensive tackle and defended the run. After a quick breather on the sideline, Barr crept up to the line of scrimmage to the "A" gap between the center and guard before dropping back to cover tight end Kyle Rudolph.

That said, the coaching staff certainly hasn't had any trouble picking Barr out of the crowd.

"We are excited with where he is right now," defensive coordinator George Edwards said. "We are seeing a lot of the flashes that you saw when we evaluated him coming out."

Much of the focus from the media and screaming fans during the first week of training camp was on the team's other first-rounder, quarterback Teddy Bridgewater, who was selected 23 picks behind Barr. But now that Barr has been elevated to the first-team defense for the foreseeable future and is looking like he belonged with the starters all along, the ninth overall pick in May's draft won't be flying under the radar for much longer.

Head coach Mike Zimmer even went as far as to say that there is a "strong" possibility Barr will start the season opener against the St. Louis Rams. "I probably would have said that after the first minicamp," Zimmer added.

Vikings rookie linebacker Anthony Barr on his learning several roles:  “The more you can do, the more valuable you are.”

Barr, who racked up 23.5 sacks and 40.5 tackles for a loss in his two seasons as an edge rusher in UCLA's 3-4 scheme, has been lining up as the strongside outside linebacker in the Vikings' 4-3 base defense since Wednesday. And as they promised the night they drafted him, they are putting his unique skill set to use all over the place, especially in their sub packages.

In the nickel, Barr has stood up like a linebacker and covered running backs and tight ends or lined up as an edge rusher with his hand in the dirt, something he estimates he did maybe twice at UCLA, and chased after the quarterback. The team has been so impressed with his instincts in coverage and his ability to stay with his man that they have used him as their lone linebacker in their dime defense, trusting him to man the middle.

"I've coached a 3-4 defense, and sometimes those outside linebackers in the 3-4 just want to rush," said linebackers coach Adam Zimmer, also the coach's son. "They just want to go get the quarterback. He understands the passing game. He understands routes. He understands what we're trying to do in the coverages."

Adam Zimmer said that despite Barr missing most of the team's spring workouts because of an NFL rule that kept him on campus, the 22-year-old is "not really behind the eight ball at all." Zimmer flew to California twice this spring to work with him in a meeting room and bring him up to speed. He and Barr also would speak on the phone while watching the same snippets of practice film on their iPads.

The coaching staff has raved about Barr's ability to retain information, which is noteworthy not only because he is a rookie, but because he played running back his first two years at UCLA. "It's a challenge. It's definitely a challenge," Barr said of learning many roles. "But it's going to benefit me because the more you can do, the more valuable you are."

While Barr has flashed at times, like he did Friday when he burst toward the inside on Kalil before countering with a spin move to open up a clear path to quarterback Matt Cassel, he also has had his share of welcome-to-the-NFL moments. A few plays after he got the better of Kalil, he ran facemask first into a brick wall wearing a No. 71 jersey while pursuing a run.

"I'm definitely more comfortable," Barr said. "But I definitely still have a lot to learn."

Mike Zimmer has nitpicked him while chatting with reporters, focusing on Barr being a little off with his alignments or pulling off his man a little too soon in coverage. Yet it's clear that he expects big things from Barr, saying he has never coached a player of Barr's size who had this diverse a skill set in his 35 years on the sideline.

"My expectations of him are probably higher than they are for anybody else," Zimmer said. "I have seen great things out of him. … He's got tremendous, tremendous physical abilities."