Mike Pettine knows a great defender when he sees one.
When the new Cleveland Browns coach watches University at Buffalo linebacker Khalil Mack, the assessment is easy.
"Explosive athlete," Pettine said last week at the NFL owners meetings in Orlando, Fla. "He's a guy that tested extremely well, but he's not a tester. He's not a combine warrior. He's a guy that the tape backs it up."
Pettine rejuvenated the Buffalo Bills' defense last year as their coordinator.
Players such as defensive linemen Mario Williams and Kyle Williams maintained a high-level of performance, while others such as defensive tackle Marcell Dareus, linebacker Jerry Hughes, cornerback Leodis McKelvin and safety Aaron Williams excelled like never before.
Four of Pettine's players went to the Pro Bowl. A fifth, linebacker Kiko Alonso, nearly won defensive rookie of the year.
Pettine did such a strong job that the Browns named him head coach after just one season away from mentor Rex Ryan.
The Browns own the fourth overall draft pick and could have a shot at Mack, the greatest player in UB history and possibly the second straight No. 1 pick from the Mid-American Conference.
"He can play on the ball. He can play off the ball," Pettine said. "He plays violently, and he's played some of his better games against better competition.
"You worry about a guy that's played in what's perceived to be a lesser conference. You worry about him kind of dominating his own, but he played real well against Ohio State."
Mack's display against Ohio State is a binky for scouts. That game is comforting because it bridges Mack's gap from MAC speculation to big-time-college, eyewitness evaluation.
Mack made a game-high nine tackles with 2.5 sacks and returned an interception 45 yards for a touchdown against Ohio State.
"When you have a guy that's a special player like that, not that he's played the same position as Mario, but what we did with Mario in Buffalo, he didn't line as up as the left defensive end all the time," Pettine said. "He was on the left. He was on the right. He was standing up. He was inside as the three. He was on the nose sometimes. We actually stood him up a couple times.
"So I think when you have a special guy like that, I think his home base will be outside. But we'll look to move him all around to take advantage of his ability."