The coach was an All-American defensive lineman at USC who became a first-round draft pick. The player is an all-conference defensive lineman at USC who could become a second-round draft pick.
The coach is a wise sage who dispenses advice tempered by experience. The player is a willing student, yet one eager to begin his own journey.
The coach is a cancer survivor whose football career was cut short by leukemia. The player has overcome a speech impediment that slowed him everywhere but on the field.
Through the similarities and the differences — or perhaps because of them — Kenechi Udeze, the coach, and Rasheem Green, the player, have formed an unusually tight bond.
"There wasn't a time that he didn't feel comfortable coming upstairs and knocking on my door," the coach said.
"Coach KU has helped me become a better person and a player. And I'm really grateful," the player said.
Now, however, the two men are relying on each other more heavily than ever. In next week's Cotton Bowl, Udeze will be counting on Green to disrupt an Ohio State offense that is averaging 524 yards and more than 42 points a game.
Then after the game, Green will turn to Udeze to help him sort out a future that is becoming increasingly complicated.
Green, a junior, is a semester shy of a college degree he may not finish if he declares for next spring's NFL draft. Yet forfeiting his senior year to turn pro could mean millions for Green and his family.
Should he stay or should he go? Publicly, Green hasn't expressed a preference. But Udeze has. And it's one influenced by his decision to leave school after his junior season for an NFL career that was interrupted by a knee injury, then ended after four seasons when he was diagnosed with a blood cancer, acute lymphoblastic leukemia, now in remission.
"It still hurts," Udeze, 34, said of his premature retirement. "But my peace is coming on the football field and still being part of the game. I love football. I love everything about it.
"The man upstairs, in my opinion, doesn't make any mistakes. So I'm really happy that he led me where I am now and I'm still part of [football] on a day-to-day basis."
In Green he has found a kindred spirit, an All-American at Gardena's Serra High who has menaced quarterbacks and running backs alike. This season he leads USC's defensive line with nine sacks and 37 tackles, nearly a third of them for losses.
With a resume like that, accompanied by a 6-foot-4, 275-pound frame, it's hard to imagine anyone would ever have considered Green timid. As a child, however, he was reluctant to talk, silenced by a noticeable speech impediment.
"Having it made me a real shy person," he said.
"It still happens. But it's way better than it used to be. Getting better at my speech has made me a more confident person. That's really helped me on and off the field."
Udeze, whose mother had a speech impediment, has helped with that as well.
"That's one of the things that I understood from Rasheem a long time ago," he said. "It's something that he has gotten better at, significantly."
Green, 20, has also taken inspiration from his coach's story — one that can be partially read as a cautionary tale about betting everything on an NFL playing career. Udeze, who left USC without a diploma, endured a circuitous journey after cancer ended his playing career, coaching in college at Washington and Pittsburgh and with the Vikings, Seattle Seahawks and Buffalo Bills before coming back to USC prior to Green's freshman season.
It wasn't his first return to the school, though. In 2010, Udeze came back to get a degree in sociology.
"It's something that we all know," Green said. "It's such a cool story that he beat cancer. It has made me appreciate each day. It makes me want to give him my all each day because the next day is not guaranteed."
Nor is Green's senior season. But after the Cotton Bowl, Udeze will begin working on that.
Scouts are high on Green's blend of size, power and quickness, which has allowed him to play both as a tackle and a defensive end and made him effective against both the run and the pass. But while he has the potential to become a dominant lineman in the NFL, inconsistency and some subtle flaws in his technique show he's not there yet.
"He has so much to gain from staying another year," Udeze said. "He's only about four or five classes away from graduating. That alone is enough for a young man who's that close just to finish. Coming back, he's only going to solidify his draft position.
"But that's a decision he has to make. It's not about me. It's never been about me but about what's best for these young men. If it's time for him to go, I'll wholly support him."