In the waning moments of No. 13 Texas Tech's game against No. 22 Arizona, the Red Raiders faced a critical opportunity to put the game away. 

First-time starting quarterback Thomas Castellanos took a carry for only a few yards on second down, pulling down the linebackers and setting up third-and-one. The Red Raiders lined up in a two-back set, seemingly setting up another quarterback run. 

Castellanos set the ball in the mesh point for a read while the defense collapsed. Instead of pulling, running back J'Koby Williams clutched the ball, took one cut right and broke off a dramatic 64-yard run to put the finishing touches on a dramatic 34-26 win to wrestle control of the Big 12 back. 

Texas Tech coach Joey McGuire made a bold move, benching quarterback Will Hammond in favor of the journeyman Castellanos. But after finding their offense in the second half, Castellanos unlocks a new ceiling for the Red Raiders heading into the home stretch. 

Castellanos was a late addition to the Texas Tech roster after receiving an injunction, primarily rostered to give the Red Raiders some experienced depth behind first-year starting quarterback Will Hammond. But several weeks into Hammond's starting tenure, results were poor. 

Despite playing a relatively light schedule, the Red Raiders ranked bottom half in the Big 12 in total offense under Hammond's watch. The running game, especially, was lackluster as defenses stacked the box and challenged an inconsistent offensive line. Hammond threw six touchdowns to six interceptions in his starts. 

While Castellanos is less of a factor in the passing game, the threat of his rushing is a game-changer for the Red Raiders. Seven of his carries went for first downs, and he broke off a pair of carries for 20-yard gains. Castellanos became the first Texas Tech quarterback to record 100 yards rushing since Tyler Shough. 

Castellanos threw for 144 yards and two touchdowns and added 117 yards and a score on the ground. But beyond the rushing production, defenses are forced to account for all 11 players. 

The switch made a huge difference for running back J'Koby Williams, who exploded for 175 yards and a touchdown in the win. The 328 yards rushing was the most surrendered by an Arizona defense since 2020, a 0-5 pandemic season under Kevin Sumlin. 

Since a 28-17 loss to BYU, the Wildcats have been on a tear. They won their last three games by an average of 28.0 points per game and rattled off a five-game winning streak. It was a prime opportunity for the Wildcats to knock off the reigning champs, coming off of a frustrating loss. Instead, Arizona gave up 34 points, the most since Sept. 27, 2025, against No. 14 Iowa State. 

To be clear, Castellanos has plenty of his own issues. The senior completed only 5 of 15 passes in the first half and 11 of 24 for the game, even below his career average of 58.5% completion. His passing is primarily a wrinkle on a run-based offense. 

Furthermore, Castellanos is still playing on a temporary injunction. Earlier this season, Castellanos briefly lost eligibility after a previous injunction was dissolved. Texas Tech can't be 100% confident that their new quarterback will stay eligible through the end of the season. 

Despite the drawbacks, Castellanos gives Texas Tech a much-needed spark heading into the home stretch of the season. With the 30-game starter in the lineup, the Red Raiders seriously re-enter the Big 12 race.