The pass-rusher's ears perked up like a German Shepherd's.
"Yes. Yes. They're showing a lot of interest," Mathis said at the NFL Combine. "They like the bigger outside backers. My agent told me that they really like me. And I've seen some articles on me for the Steelers. I've got to run a good 40 at my pro day. They're waiting to see me run."
They had to wait a long time because Mathis didn't run at the Combine. He had torn a toe ligament in his right foot last October and missed the second half of last season.
In the first six games, Mathis had 30 quarterback pressures, 5 sacks, 7.5 tackles for loss, 25 tackles, 17 solo tackles and 0 missed tackles.
He drew raves from the analysts:
And he appeared to be on his way to his breakout season.
He had started only seven games prior to 2016 as a defensive end, while one of last year's Steelers draft picks, Travis Feeney, played the more coveted (for those who consider themselves pass-rushers) outside linebacker position.
"I was playing 4-I last year, pretty much like a D-tackle, and then they moved me outside as a 3-4 outside backer," Mathis explained.
It was a gift from a coaching staff Mathis had once walked out on.
Recruited out of Southern California by Steve Sarkisian, Mathis didn't appreciate a coaching change after one year to Chris Petersen. He tweeted out that he wanted to transfer, and then wondered why he wasn't getting much playing time after opting to stay.
The conflict peaked when Mathis left the team during the 2014 season -- reportedly to be with his ill mother -- and was suspended for two weeks.
But Mathis returned, played, started those seven games in 2015 and appeared on his way to stardom in 2016 before the foot injury.
“Having the wrong people around you," was how Mathis explained his immaturity to the Seattle Times. “I was angry at the world, always asking, ‘Why this, why that?’”
But his attitude changed.
"The guy's done a damn-near 180," his defensive coordinator, Pete Kwiatkowski, told the paper.
"I feel like growing up, becoming a father and a husband, that's what really changed me," Mathis said at the Combine. "I had my son during the summer, a week before fall camp, and it just changed me. It changed my motivation, my mindset, everything.
"I'm going to make sure my family's going to be able to eat, have food on the table, have clothes on their back. Even though I'm tired from being up with the baby all night, I'm going to go out to practice and bust my butt because it's bigger than me."
The foot healed in time for the Combine, but Mathis was overweight at 266. He had just started running again and was looking forward to a mid-April pro day with the plan of weighing 250.
That plan, though, didn't appear to come off.
Oh, the workout did. But not the weight loss.
Without fanfare, his agent released a video of the workout and it shows Mathis breathing heavily and struggling. The results weren't released.
Mathis goes by JoJo, and his son, his life preserver, is JoJo IV. His father, JoJo II, is a lifelong Steelers fan. That's why Mathis was so happy to meet with the Steelers' outside linebackers coach at the Combine.
"Yeah, Joey Porter, I met with him last night," Mathis said. "It was a good conversation. He was one of my childhood favorite players, my dad's favorite player of all time. My dad's a Steelers fan, so it was pretty fun going to talk to him and pick his brain and stuff. It was a blessing to be able to meet him."
But will Mathis meet with him next week?
That's another big question for one of the draft's greatest enigmas.
(For the full breakdown on the defensive line from SteelCityInsider, click here.)