UCLA sophomore guard Isaac Hamilton could hear him taunting Arizona's Stanley Johnson.
"You ugly!" Parker was saying.
Then, to Arizona's Rondae Hollis-Jefferson, again, "You ugly!"
No one, teammates or opponents, knew how to react except with amusement.
"Sometimes," Hamilton said, "you can get uptight, you can be into yourself. Then [Parker] cracks a joke, you just have to laugh. It makes you want to play with this guy."
Earlier in the season, the Bruins were crushed by their own anxiety. Hamilton, trying to be perfect, would implode under pressure. Bryce Alford went cold. On a big stage against North Carolina, and later against Kentucky, the team curled into a shell.
As UCLA has recovered on its way to a surprising berth in the NCAA tournament, Parker has been a burst of comic relief, the team's jester. The junior has critiqued teammates' looks, raved about his taking a charge and declared himself a mixture of Golden State Warriors All-Stars Stephen Curry and Klay Thompson.
Between games, the 260-pound Parker goes to yoga occasionally and cracks wise continuously.
Asked to repeat some of Parker's jokes, freshman center Thomas Welsh said, "I don't know if there's very many I could say in these circumstances."
Parker's constant chatter, teammates say, puts them at ease.
Before the Bruins' most pressure-filled game to date, Thursday's second-round South Region game against sixth-seeded Southern Methodist, they will again rely on Parker's calm.
As for the court, UCLA Coach Steve Alford has called Parker the team's most important player, akin to the Bruins' rudder. For better or worse, UCLA has followed Parker's direction.
When Parker injured his back and did not travel on a road trip against Oregon State and Oregon, the Bruins were adrift. Normally, said freshman forward Kevon Looney, Parker is there to crack jokes before the game.
But Parker was watching from Westwood and throwing shoes at the television.
"Without Tone," Looney said. "I think people were more nervous."
"It was quiet," Bryce Alford said.
UCLA lost both games, by a combined 29 points.
When Parker returned, UCLA picked up its best win of the season, against Utah. Parker had only four points and six rebounds in 25 minutes, but with him in the lineup, UCLA's offense had evolved from a one-dimensional, perimeter-heavy attack to a more balanced look.
When Parker touched the ball, he drew double teams and freed up the guards.
"That's when our offense is working best," Bryce Alford said. "When we can get the ball going inside out, I think we're a very dangerous team."
SMU presents the best frontcourt defense UCLA has seen since perhaps the Kentucky game in December. In fact, the Mustangs block a higher percentage of shots at the rim (19.8%) than Kentucky, according to Hoop-Math.com — and the Wildcats blocked 13 shots against the Bruins.
SMU's big men are athletic and active enough to take away UCLA's rebounding advantage. And 6-foot-10 forward Cannen Cunningham of SMU said they don't feel they've reached their potential.
"Coach [Larry] Brown tells us we don't block enough shots," Cunningham said.
SMU has the No. 25 scoring defense in the nation, but those numbers are inflated slightly by its slower pace. In points per 100 possessions, SMU is 42nd after adjusting for competition, according to Kenpom.com
The Mustangs' point guard, Nic Moore, is also dangerous. He averages 14.2 points and 5.2 assists per game, but he has gone cold in March, in which he has shot just 27.3%.
So the game could hinge on the frontcourt battle. And with Looney still adjusting to playing with a mask after sustaining a facial fracture, Parker may again be UCLA's bellwether.
Parker did not seem to feel any pressure. Before UCLA's light practice Wednesday, he stalked around the locker room with a video camera, posing as a reporter and interviewing teammates.
"It's a tough job," Parker said, "but it's good to ask these young kids questions."
He was working on a story, he said, on Welsh's pants, a pair of capri-length sweats. Parker had worn a nearly identical pair the day before, "but mine has a little bit of a different sauce to it," Parker said.
"We're still working on Tom's swag," he explained.
Nearby, Hamilton read a magazine at his locker and chuckled.