When USC coach Lincoln Riley told his players a few days ago that walk-on center Kilian O'Connor was going on scholarship, his teammates mobbed him in the Trojans' weight room in uproarious celebration.

The kind of reaction that can only come when the rest of the team knows full-well the work it took to bring that moment to fruition.

The walk-on going on scholarship moment happens almost every year at college programs around the country, when a team is under its scholarship cap after the transfer portal cycle and takes the opportunity to reward a deserving player who has been paying his way through school.

Kicker Denis Lynch and wide receiver Josiah Zamora were other recipients of that "promotion" during Riley's tenure.

O'Connor might be the most deserving case I can remember, though.

USC has loaded up on offensive line recruits in recent classes, both in terms of four-star talents and more raw prospects the staff still felt deserved the investment of a scholarship spot.

Yet, it was the walk-on O'Connor who emerged as one of the few established backup offensive linemen on the roster last year on a perilously thin depth chart and the clear-cut second option at center behind veteran Jonah Monheim.

With Monheim unavailable for the bowl game, O'Connor made his first start and held up pretty well over 74 total snaps in the Las Vegas Bowl win over Texas A&M, allowing 3 pressures but 0 sacks. It wasn't flawless, but he looked the part, for sure.

Given the considerable resources college programs put into recruiting and signing offensive linemen, normally having close to a three-deep of scholarship players across the unit, it may be the position aside from quarterback least likely or conducive to a walk-on ever starting a game.

O'Connor, who played at Santa Margarita Catholic HS in Orange County, never saw it that way, though.

He was asked last spring, when it had become clear he was the No. 2 center for the Trojans, whether he truly thought there was a path to playing time when he joined the program in 2022.

"I did because I knew that I'd work hard to get there," he said. "I knew it wasn't going to be easy, but I knew when I came here I wanted to play at the highest level possible. That's why I'm here."

O'Connor noted that he had other preferred walk-on opportunities and some "smaller-level offers, but at the end of the day I wanted to play at the highest-level ball that I could," he said. "I knew that I'd have a shot here."

Riley, meanwhile, shared with the team the backstory of how they learned about O'Connor soon after taking over the program.

"A couple years ago, I got a call from a local high school coach -- guy that I know and respected, recruited his school for a long time, that told me there was this cat here in town that was getting overlooked and we need to take a look at. And he was exactly right," Riley said, before announcing the scholarship news.

O'Connor then addressed his teammates -- once the collective celebration had run its course.

"I really don't got a lot to say -- just so thankful for this opportunity," he said. "... My dad was a walk-on, my grandpa was a walk-on and, you know, it's something that's really special for me. I thank you guys every day for making it easy to show up."

O'Connor is a classic example for any high school football player to look to as motivation.

He's slated to be the backup this year again with USC bringing in Syracuse transfer J'Onre Reed to take over for Monheim, but that's an important role on the depth chart as is.

And quite a statement, again, that O'Connor has now been at USC through four incoming recruiting classes of four-star and three-star signees and he's still in that position.