MANKATO, Minn.– Antone Exum’s confidence long has been evident. While at Virginia Tech, he recorded a rap song with the verse, “I’m the best corner in the country and you know it.”

Exum is now a safety, having been moved from cornerback last year as a Vikings rookie. As for his confidence, he realizes he perhaps has needed to tone things down a bit.

When Minnesota coach Mike Zimmer recently was asked about Exum, he said he has improved as a player and with his maturity. The coach said he needed to have several talks with Exum when he was a rookie.

“We had a couple of guys last year that came in here as rookies that really didn’t know how to act,” Zimmer said. “He was actually one of them. He has grown up a lot. Now it seems important to him. It seems like he’s understanding what the coaches want.

“Some guys, they come into the league and they think they’ve made it and they don’t understand what you have to do to become a professional football player. I had several talks with him, but finally I think he has figured this stuff out a little bit.”

Zimmer wouldn’t offer specifics about the conversations. When Exum was shown a transcript of the coach’s remarks, he also didn’t provide specifics but wondered if he might have showed up in the NFL a bit too cocky.

“I was coming in and being young and not knowing the ropes,” Exum said. “I’m an energized guy, so maybe controlling that energy (was needed). I’m real confident on and off the field, so maybe taming that a little bit. So maybe that’s what (Zimmer) was referring to. I’ve had a lot of talks with him about everything I’m asked to do.”

Regardless, Exum and Zimmer now seem to be on the same page. Exum said there’s no doubt he’s “matured since last year.”

Soon, it will be seen whether he’s done enough to win the starting job at strong safety.

Exum had a strong first week of training camp while battling incumbent Robert Blanton and Andrew Sendejo for the spot. Exum mostly has been running with the second team behind Blanton, but did get some work Sunday with the first unit.

“He looks good, looks great,” Blanton said. “Everybody’s out there competing and trying to have a great camp.”

Exum believes he has good shot at winning the job. After all, he hasn’t completely toned down his confidence level.

“I think so,” he said. “I think it will be a pretty good battle. We’ve got a lot of talented guys back there, so it’s something to definitely watch. … I do (have a good chance). I’m just out there trying to get more consistent and do what the coaches want and are asking me to do. I think the person that does it to the best of their ability at the end of the day will be the starter.”

Zimmer won’t elaborate much on how the competition is going. He did say that preseason games, starting next Sunday against Pittsburgh in the Hall of Fame Game in Canton, Ohio, will be important.

Blanton was ranked a solid 17th out of 82 safeties by Pro Football Focus last year, but the Vikings seemingly don’t look at him as a long-term starter even though he is only 25 and entering just his fourth season. Meanwhile, Minnesota general manager Rick Spielman went out of his way last May on the final day of the NFL draft to note the strides Exum had made since being a rookie.

“We’re very excited about the progress he has made,” Spielman said at the time. “Exum is someone we’re definitely going to be keep a close eye on.”

Exum worked plenty between the end of last season and April, when players reported for spring drills. That included ample film study as he continued to learn the intricacies of a new position.

“I worked hard physically and mentally,” said Exum, a sixth-round pick in 2014. “I attacked my offseason. As far as my workouts were concerned, I think I probably I had the best run that I ever have had. Mentally, every single day I was watching film. No matter what I was doing, I would get my film work in.”

That included sessions with his iPad in his hometown of Richmond, Va., and while working out in the Phoenix area. Some of his Arizona sessions were with notable defensive backs coach Will Sullivan, who has mentored Darrelle Revis of the New York Jets.

Exum looks up to Revis. In fact, at Virginia Tech he wrote and performed a song called “Revis” in which he claimed similarities to the star cornerback.

Exum has written some additional rap lyrics since entering the NFL but hasn’t recorded them. He wouldn’t say what they’re about, but considering some of the strides he has needed to make to appease Zimmer, one might think they don’t include comparisons to an all-time great safety.

Follow Chris Tomasson at twitter.com/christomasson.