Pachall has been out since Sept. 7 after breaking his non-throwing arm in the Horned Frogs' second game of the season. Pachall has been out of a cast for a month and has been working as TCU's scout-team quarterback.
Since Pachall's injury, the TCU offense has become one of the most ineffective in college football. Behind quarterback Trevone Boykin, who has started since Pachall's injury, the Horned Frogs rank 111th in the nation in total offense.
They have also been shut out in the first half in three of their four Big 12 games, which has resulted in a 1-3 start in the league.
Texas coach Mack Brown said this week that the Longhorns were preparing for both quarterbacks in case Pachall was cleared to play.
"Because they're different, it makes it more difficult to prepare," Brown said. "It is more difficult for the unknown."