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By now, Utah's defensive tackles have seen enough footage of Joe Jackson running wild against the Utes that they probably see the Kansas State running back in their nightmares.
In one of the most stunning performances ever against a Ute defense , last season Jackson rushed for 293 yards and three touchdowns. Other K-State players combined for 179 yards for a total of 472 rushing yards. Even more incredible was the fact that Utah pulled off a wild comeback victory .
The next week, Kansas rushed for 290 yards in another game the Utes won.
Utah is normally stingy against the run, but in 2025, it ranked No. 108 in the country in rushing yards allowed per game, 181.2. While the numbers were heavily skewed by the final two regular-season games, the Utes are not used to seeing so much rushing success against them.
Those two huge rushing performances largely stemmed from poor play from Utah's defensive tackles and poor tackling from the safeties. Making sure that doesn't happen this season has been a huge point of emphasis for defensive coordinator Colton Swan and defensive tackles coach Luther Elliss in the offseason.
"We've been watching a lot of old film from last year, like K-State. They really ran a lot of yards on us," said sophomore defensive tackle Pupu Sepulona. "We had to really fix up on how to not make those same mistakes again for this season."
On film, it was glaringly obvious.
"Especially for example, how guards would pull and we would just shoot the gap and the other gap would expand," Sepulona said. "One thing about our DC, coach Swan, and also my position coach, coach Elliss, they recommend us D-tackles to play with hands, play with technique and not shoot the gap."
Perhaps the youngest group on Utah's team, the defensive tackles are the biggest question mark. Gone from last season are Aliki Vimahi (graduated), Jonah Lea'ea (transferred to Michigan) and Dallas Vakalahi (transferred to Penn State). That's a lot of departing experience, but the room is not barren.
Freshmen Karson Kaufusi (177 snaps) and Sepulona (137 snaps) got extremely valuable experience in their first collegiate seasons. Kaufusi totaled 13 tackles and 0.5 sacks, while Sepulona had 13 tackles and a tackle for loss.
Heading into his freshman year, Sepulona didn't think he'd play very much, but due to some injuries in front of him and a large number of Utah blowouts, he saw a good amount of time in his first season.
He earned a spot on the travel squad to open the season, which built his confidence. He got his first college snaps in Utah's opening blowout win against UCLA, but against Cal Poly, he felt like things started to click, registering his first tackle for loss.
Utah Utes defensive tackle Pupu Sepulona (45), right, celebrates after the Utah Utes beat the Nebraska Cornhuskers in the Las Vegas Bowl at Allegiant Stadium in Las Vegas on Wednesday, Dec. 31, 2025. | Tess Crowley, Deseret News
Sepulona had four-tackle games against West Virginia and Colorado, and notched another tackle for loss against the Buffaloes.
"Being able to be on the travel squad really built my confidence," he said. "From there, playing and getting playing time in the games against UCLA, Cal Poly, Wyoming, West Virginia, Colorado, Texas Tech, and all against big schools in the Big 12, that really built my confidence and (let me) really see my talent against the other talented players from other schools."
Aside from the games, Sepulona was going up against one of the most talented offensive lines in the country every day in practice, which helped him further refine his game at the college level.
As expected with any freshman, there were ups and downs (Sepulona had a Pro Football Focus grade of 59.5 on the season), but the games against West Virginia and Colorado showed a glimpse of his potential.
Since the Las Vegas Bowl win versus Nebraska, Sepulona and the rest of the defensive tackles have been hard at work, especially in the weight room with strength coach Steve Saunders .
There's a lot more size in this year's group — Sepulona is 298 pounds, Kaufusi is 305, Wyoming transfer Lucas Samsula is 306, Tennessee transfer Jamal Wallace is 313 and Dilan Battle is 320.
"The strength coaches did an excellent job in helping them to get on the mass, to get bigger, get stronger, but not lose speed or quickness, and it's translating to the field currently right now," Elliss said.
San Jose State transfer Jireh Moe is the exception in the room at 280 pounds, but he brings explosiveness that makes him hard to block.
Moe, a sophomore, registered 28 tackles and 1.5 sacks. He was the highest-graded SJSU defensive player by Pro Football Focus, earning a 83.2 grade and is in the mix for a starting job for the Utes. Samsula, also a sophomore (28 tackles and 1.5 sacks) should also be in the rotation with Sepulona, Kaufusi and Moe.
Utah is counting on Kaufusi and Sepulona to make big jumps in their sophomore year, and also need some of the transfer players to make an impact.
"The room is progressing right now. I believe that we're getting better and better every day. We just got to keep on stacking days," Moe said. "Yes, we have a chip on our shoulder. We got lots of to prove, and we're going to prove it."
Until the results show in games, there's going to be doubts about the group, but the D-tackle room is confident in its ability.
"Everybody has a role and I feel like our room has so much potential to ball out this season," Sepulona said.
Utah defensive tackle Pupu Sepulona runs through drills during the first day of fall camp, Aug. 3, 2026. | Davis Kuhn, Utah Athletics
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