Before Gross retired, he was a widely respected leader who served as liaison between players and coaches.

When he stepped away, Kalil stepped in.

"He's filled the role that I vacated," Gross said. "He picked up where I left off and took it to another level."

Gross admits it's hard to put into words exactly what goes into being "that guy" in the locker room, that guy everyone looks to for, well, everything.

"I can tell you that being an offensive lineman in the NFL is an incredibly tough job when all you have to worry about is yourself. Then if you choose to take on the role of uplifting teammates and watching extra film with young guys, rah-rah during practice, making sure everybody is on time when they need to be, well that makes your job even more taxing," Gross said.

"Putting out fires – all of that is exhausting."

Head coach Ron Rivera has often made mention of Gross and Kalil's invaluable perspective.

"As much as Coach Rivera would love to say he has a pulse on the team, he doesn't know all the conversations that go on in the locker room, in the huddle or on the sideline," Gross said. "Ryan is somebody that Ron can come to and ask, 'How are guys doing?' That's not easy. A lot of guys wouldn't want to be that guy on the team. But Ryan knows that that's needed."

Kalil also knew more would be required of him when the Panthers selected quarterback Cam Newton with the No. 1 overall pick in 2011.

Newton was transitioning from a spread offense at Auburn and he had a lot to learn, from taking snaps under center more frequently to identifying pressures.

"When we brought Cam in, Ryan's load grew exorbitantly with the protection calls and things like that," Gross said. "He was so good at it that I think the plan was to take that away from him as Cam got more comfortable, but Ryan was just so good at it they kept it on him."

And for that, among other things, Newton has always been grateful.

"Everything goes through Ryan Kalil," Newton said back in 2016. "He's made my life extremely easy.