We're walking through each Big 12 team and identifying its most irreplaceable talent on the blog right now. He's the guy they can least afford to lose and the guy to whom an injury or departure would have the most effect.
Let's move on with Texas.
Most indispensable player: QB David Ash
Texas is pretty close to being one of the most complete teams in the Big 12 on paper, but Ash holds a lot of that together. The Longhorns have legitimate Big 12 title aspirations, but it's not happening with Case McCoy at quarterback for the conference season. Ash is the Big 12's most experienced quarterback with 18 career starts, and though he's had consistency issues throughout those starts, he's shown the potential to be way, way above average. Critique Ash's shortcomings all you want, but he's definitely good enough to win a Big 12 title considering the team around him, and no other quarterback on Texas' roster can say that. Unless they've got a big lead in the standings late in the season, an injury to Ash means saying goodbye to the Longhorns' Big 12 title hopes. No other position has a player that integral to the team's overall success.
The Longhorns have some promising freshmen on the roster in Tyrone Swoopes and Jalen Overstreet, but no doubt about it: Texas' most indispensable player is Ash.