"You can see it out there," junior linebacker Jared Norris said. "His ribs are showing."
But what Masina lacks in bulk, he makes up with quickness. Manning the stud linebacker position for the better part of spring, he has a knack for getting to the play, even if he has to run across the field. And he doesn't lack for a ferocious hit when he needs one: In Tuesday's practice, he made a touchdown-saving tackle at the goal line.
Not bad for a skinny underclassman still trying to pack on pounds.
"They're trying to keep me as fast as I was in high school, and it's hard to put on weight and maintain my speed," Masina said. "I just got to keep getting bigger, keep getting stronger and bring it."
Spring has been the season for Masina to show his stuff so far. With a knee injury to Jacoby Hale, Masina is getting top-string reps in the linebacking corps. After notching a grand total of seven tackles as a true freshman, it's needed experience.
For Masina, it's been about digesting the mental aspect of the game. As a true freshman, plays took time to process. He had moments of hesitation, of indecision.
This year, he's begun to appreciate the subtleties of the game: how a slight change in alignment can make a huge different between a successful play and a broken one.
"That first year is always rough, having not to think, just going off the bat when you see it," he said. "Now that's what I'm doing, whereas last year I had to think."
The Utes were excited to get the Brighton prospect just over a year ago when he signed.
Since then, he's shown his potential early.
While he might not start once some other linebackers get healthy, he's making a push to get more reps and carve a bigger role for himself come fall.
"You see him running all over the field chasing kids down and making tackles," Norris said. "I guess he just needs to be more of a coach on the field, learn the defense a little more than he has now. He's getting it down."
Once he adds some girth, the coaching staff sees him as an integral part to the defense's future.
For now, those flashes of brilliance are encouraging.
"I'm really excited about Uaea Masina," defensive coordinator Kalani Sitake said. "He's going to be a really good player for us."