Before the 2024 season, Simmons was listed on the preseason Shaun Alexander Freshman of the Year watchlist.[7] Simmons earned immediate playing time as a freshman. During week five of the 2024 season, Simmons recorded 7 tackles and 2 sacks against Mississippi State.[8] In the first round of the 2024-25 College Football Playoff against Clemson, Simmons logged one interception. In the Peach Bowl College Football Playoff quarterfinals, Simmons had one sack and five tackles.[9] At the end of the season, Simmons was named the Shaun Alexander Freshman of the Year, Freshman All-American, and SEC All-Freshman team.[10]
Before the 2025 Season, Simmons was named to the Lott Trophy, Bronko Nagurski Trophy, Walter Camp Award, Chuck Bednarik Award, and Lombardi Award watchlists. He was also named to the preseason All-SEC first team and preseason All-American first team.[11][12] In the Red Rivalry Game against Oklahoma, Simmons recorded five tackles and 2.5 sacks, earning SEC Co-Defensive Lineman of the Week.[13][14] After Week 7, he was selected to the midseason watch list for the Lombardi Award.[15] In the overtime win against Kentucky in Week 8, Simmons posted a career high three sacks and his first forced fumble of the season, earning him SEC Co-Defensive Lineman of the Week for the second time in a row.[16] In Week 10 against Vanderbilt, Simmons posted a strip-sack and fumble recovery, 1.5 tackles for a loss, and five tackles, earning him SEC Co-Defensive Lineman of the Week, making it the third time he received the honor in four weeks.[17] In Week 13 against Arkansas, posted five tackles, 1.5 tackles for a loss, a career-high four pressures, and a sack-fumble that was returned by a teammate for a touchdown, earning him SEC Co-Defensive Lineman of the Week.[18] At the end of the season, Simmons was named to the All-SEC first team.[19]
| Season |
GP |
Tackles |
Interceptions |
Fumbles |
| Solo | Ast | Cmb | TfL | Sck | Int | Yds | Avg | TD | PD | FR | Yds | TD | FF |
| Texas Longhorns |
| 2024 |
16 | 31 | 17 | 48 | 14.0 | 9.0 | 1 | -2 | -2 | 0 | 2 | 0 | 0 | 0 | 3 |
| 2025 |
13 | 23 | 20 | 42 | 15.5 | 12.0 | 0 | 0 | 0 | 0 | 2 | 1 | 0 | 0 | 3 |
| Career | 29 | 54 | 37 | 91 | 29.5 | 21.0 | 1 | -2 | -2 | 0 | 4 | 1 | 0 | 0 | 6 |