He's been coaching for almost 40 years and while most of that has been in college, Greg Mattison knows an exceedingly talented defensive lineman when he sees him.
Now Mattison is the defensive line coach at Michigan, but for two seasons he coordinated the defense for the Baltimore Ravens at the same time new Detroit Lions defensive tackle Haloti Ngata was entering his prime.
Ngata -- and the rest of the Detroit defense -- has a difficult task in trying to replace the attention given and production provided by Ndamukong Suh, who left the Lions earlier this month for Miami in free agency. Suh's departure prompted the Ngata trade.
"I don't know if you say you replace somebody," Mattison told ESPN.com's Dan Murphy on Thursday. "What Haloti Ngata brings is Haloti Ngata. He doesn't have to compare himself to anybody. I've always felt he's one of the best defensive tackles ever to play. I'm just really excited about him being there."
He also echoed the Detroit front office and some of Ngata's former teammates in expressing the high quality person Ngata is. He's played in 151 career games (including playoffs) and made 494 tackles with 29 sacks and five interceptions.
Detroit's players believe Ngata's presence will help the loss of Suh, who was a critical piece for creating a defense that was in the top 10 in almost every major category in 2014.
"Having someone plug in, having someone plug in that gap, that's always the key," cornerback Rashean Mathis said. "In any business field, regardless whether sports or not, if you lose a few key pieces, what makes you successful? Having someone step up and plug in that gap.
"That's the only way that you're able to be as successful as you were before, having someone step up."
The Lions plugged holes left by injury extremely well during the 2014 season. But this is a defense that will enter 2015 with four critical players -- Ngata, linebacker Stephen Tulloch, safety James Ihedigbo and Mathis -- will be at least 30 years old. Turning 30 is usually the demarcation line for a decline in play.
So that'll be something else to watch as Detroit's defense moves on from Suh.
And now, a look around the Interwebs in search of Lions and other sports news:
Mathis returns to play and potentially groom his successor. The Rams added former Detroit offensive lineman Garrett Reynolds. The Lions hosted cornerback P.J. Williams on a visit. Martin Mayhew explains why he thinks the replay proposals will fail.
The Detroit Free Press finds pictures of linebacker Stephen Tulloch's new home.
Believe in Jim Caldwell's ability to develop talent, writes Kyle Meinke of MLive.
And in NCAA stories, if you wonder where referee Ted Valentine is this offseason, this story from Gene Spakoff of The Post and Courier finds him trying to spend time with his dying brother.