Stevenett was held scoreless on 0-of-10 shooting against the Frogs.
"Thomas did a heck of a job," Johnson said. "He has a great understanding of what we're doing. I couldn't be happier for him, because I can tell you this, we don't win the game if he doesn't play well."
Abron said TCU understood stopping Stevenett would be key Thursday night.
"We knew (Stevenett) was the head of the team, and what we had to do was just chop off the head," Abron said. "So we just put pressure on him."
Heuir was the offensive force for Southern Utah, leading all scorers with 25 points on 7-of-14 shooting.
"He was consistent for the most part," Anderson said. "But a lot of it was just breakdowns on defense on our part. They had a set play that we all knew was coming through scouting reports and we just didn't buckle down and get it done."
Southern Utah head coach Nick Robinson, who served as an assistant under Johnson at Stanford, said Heuir's impact is something the Thunderbirds need from the rest of their players.
"Damon's been very aggressive over the last three or four games," Robinson said. "He struggled early but his confidence has gotten better. He's being more consistent, which is a great thing. We need more guys to be as consistent as he is."
Cheesman had 13 rebounds. Southern Utah shot 27 percent in the second half and 33 percent overall.