CHARLOTTE, N.C. — Ben Boulware has a message for NFL teams: You made a mistake.

The linebacker who was the heart and soul — as well as the leading tackler — for the national champion Clemson Tigers defence last season has plenty of motivation after going undrafted.

"I'm in the business of proving people wrong, so I'm looking forward to doing that," Boulware said.

The 6-foot-1, 229-pound Boulware wasn't drafted despite winning ACC defensive player of the year honours and earning Defensive MVP in Clemson's 35-31 win over Alabama in the College Football Playoff national championship game. He signed with the Panthers as an undrafted free agent shortly after the draft and participated in this past weekend's rookie minicamp.

He looked at home at linebacker.

"Being overlooked in every aspect of life, especially football — (people) saying 'you're not good enough, you're too small, you're too short, not athletic enough.'" Boulware said of his motivation. "Wanting to prove myself right and everyone else wrong that I can play at this level."

Boulware caught Panthers coach Ron Rivera's attention right away at minicamp.

Rivera said Boulware was making calls that most players don't pick up until after their third or fourth installation and it was obvious he's a "tremendously smart" player. He also said Boulware made his presence known on the field as a vocal leader.

"No wonder why he was on a national championship team," Rivera said.

Boulware was a two-year starter and defensive captain at Clemson, and led the Tigers with 116 tackles and 11 1/2 sacks last season. He won the Jack Lambert trophy for the nation's top linebacker, while also earning ACC Defensive Player of the Year honours.

Still, he faces an uphill battle to claim a roster spot as most undrafted rookies do, although it's not entirely impossible. The Panthers have had a number of undrafted rookies make the roster and become contributors over the years.

It helps that Carolina didn't draft any linebackers as they look to fill the void of top backup A.J. Klein, who signed earlier this off-season with the New Orleans Saints as a free agent.

If Boulware makes the roster, he'll learn from two of the game's best in former NFL Defensive Player of the Year Luke Kuechly and former All-Pro Thomas Davis — two players he grew up watching as a Panthers fan in Anderson, South Carolina, about a two-hour drive from Charlotte.

Boulware has used perceived slights against him as motivation in the past.

When ESPN college football analyst Desmond Howard called Clemson's linebackers the "Achilles heel" of the Tigers' defence last December, Boulware responded by getting a tattoo of the national championship trophy on his heel after Clemson's win.

"I proved that in college when everyone said I couldn't play at Clemson and I wouldn't contribute," Boulware said with an undeniable hint of pride in his voice. "Y'all obviously know what I did at Clemson. I know the NFL's a whole new level but I'm up for the challenge."

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