LOS ANGELES — The only time his legs found a seat last weekend in Champaign, Illinois, was for 60 measly seconds, and USC forward Saint Thomas found himself laboring amid USC’s upset bid. He’d played the most minutes of anyone in a Trojans jersey. And midgame, naturally, he asked coach Eric Musselman for a break.

Denied.

“He said if I wanna be an NBA player, I gotta suck it up,” Thomas said after USC’s win over Iowa on Tuesday.

Teammate Desmond Claude grinned next to him, USC’s point guard having just played every single second in defeating the Hawkeyes.

“Shoot,” Claude smirked, speaking of Musselman, “he did that to me today.”

He has done this, in fact, for years, the 60-year-old Musselman operating with a trust in his veterans’ legs and a no-nonsense approach to substitutions that harkens to his earliest days in the profession. Look at a box score from one of his old Nevada teams, Musselman cracked after that Iowa win: Twins and future NBA wings Caleb and Cody Martin “never came out of a game,” he said. At Arkansas, former assistant Gus Argenal remembered, Musselman would sometimes act like he couldn’t hear a player if they asked for a sub. He’d simply turn away.

Sure, that might have drawbacks. Musselman acknowledged, smiling, that a “couple guys might’ve been exhausted” after USC’s defense slipped toward the end against Iowa. But Thomas and Claude, and a heap of transfers, had come to USC to play for Musselman specifically for the trust he’d expressed in them. He’d put the ball in their hands. He was “letting us rock,” Claude said, as USC’s offense has suddenly erupted across an eight-game stretch in which the Trojans are averaging 84 points a game.

That will mean a heavy dose of heavy minutes. And the occasional back turned on a request for a sub.

“He said, ‘Nah, Tom Thibodeau don’t do this,’” Thomas said Tuesday, recounting Musselman’s words to him in Illinois. “Like, ‘You gon’ stay in the game.’ ”

It’s no random reference, as the New York Knicks head coach is still one of Musselman’s best friends. Over three decades ago, Musselman joined his late father Bill Musselman’s staff with the expansion Minnesota Timberwolves. On staff already was a young Thibodeau, whom Bill Musselman had plucked from Harvard.

The younger Musselman lived on the seventh floor of Hennepin Crossing Apartments, in downtown Minneapolis, in the Timberwolves’ second season in 1990-91. Thibodeau lived on the sixth floor. When Musselman was leaving his apartment, he’d stomp the floor to alert Thibodeau, and the two would run to the Target Center together. They played pickup ball at a health club five or six days a week with Bill Musselman, the runs becoming the stuff of local Minnesota legends.

They were all on staff together for just one year. But that year still trickles into how Musselman and Thibodeau operate, shared branches on a Bill Musselman tree that’s lived throughout modern basketball long after his death in 2000.

“Something now that he’s passed, especially — it’s so, so important, that timeframe,” Musselman told the Southern California News Group in the summer.

Bill Musselman, simply, was a different guy, as fellow former Timberwolves staffer and former Milwaukee Bucks general manager John Hammond put it. He had his own way of doing things. In life. In coaching. In Minnesota, Bill Musselman built his roster in part from veterans he’d coached previously with the CBA’s Albany Patroons. He did not tank, even as the Timberwolves struggled; he played former guard Tony Campbell, who averaged 23.2 points a game, nearly 39 minutes a night.

Musselman would tell his staff stories, Argenal remembered, of him and Thibodeau trying to convince Bill to play other players. Younger players. Musselman’s father wouldn’t do it.

“He was playing the best guys he thought were capable of getting it done, night in and night out,” Campbell remembered. “That was —that was his stance on that.

Eric Musselman, he’ll tell you himself, is his father’s son — a “copy of his dad,” as former Timberwolves center Randy Breuer put it.

At USC, Musselman leads the Trojans (11-6, 3-3 Big Ten) into a key Big Ten stretch, starting with No. 24 Wisconsin today.

Claude and backcourt mate Wesley Yates III each played all 40 minutes against Iowa. Thomas and Chibuzo Agbo each played at least 37.

Two months after Musselman started the season tweaking the minutes of 11 or 12 Trojans, he played just seven against Iowa. And if Thomas or Claude are declined a sub again, they’ll in some way have Thibodeau and Bill Musselman to thank.