LOS ANGELES — They could not be more different, and yet they are one and the same, the 5-foot-5 spittle-spewing coach on USC’s sidelines and the 6-7 effusive man in the mask.

Saint Thomas is an emotional player, coach Eric Musselman reflected in mid-October. Maybe that’s why they’ve connected as they have. Musselman, a man who’s come in for pregame speeches in his short USC tenure sporting beach chairs and boxing gloves to make points on separate occasions, hates a quiet locker room. Thomas, often, is the loudest one in any locker room.

“He’s just a guy,” Musselman put it in mid-October, “that loves to play.”

It’s been a strange road to USC for Thomas, a forward who once stepped away midseason from Loyola Chicago, dipping his toes in NBA draft waters this spring after a breakout junior year at Northern Colorado only to wind up back in the portal. But he’s shouldered an immediate role as a leader on a new USC roster — even more so, a true heartbeat — and his love to play poured out cardinal-red on USC’s home floor Thursday night in a 75-69 win over Idaho State.

He was recruited by Musselman not just as a forward, whereas Thomas often felt pigeonholed by coaches in their evaluations. He was brought to USC to play positions one through five on a versatile roster teeming with wings. In the summer, when Xavier transfer guard Desmond Claude was sidelined after an elbow procedure, Thomas shouldered the majority of point-guard reps.

“I mean, at first, I didn’t really know that he could pass that well,” freshman Jalen Shelley said of Thomas in early October.

The majority of the collegiate basketball world didn’t know, either, until point-guard Claude was benched often with foul trouble Thursday and Thomas suddenly just became USC’s point guard. For the better part of an otherwise sloppy first half, the mask-wearing forward orchestrated USC’s offense, fulfilling Musselman’s mad visions and whipping skip passes and dump-offs galore. He scored 10 points, had 9 assists and 7 rebounds, leading USC in the latter two categories. Josh Cohen led USC (2-0) with 19 points.