The game was the first since Mittie departed for Kansas State on Tuesday. Mittie won 303 games in his career at TCU, which is a school record.
Associate head coach Brian Ostermann served as interim head coach on Wednesday night.
The Frogs trailed by as much as 17 with 16:43 left in the game. They never quit though, rattling off a 15-1 run midway through the second half to tie the game up at 59 apiece.
The Buffs answered the call by outscoring TCU 19-12 in the game’s final five minutes. They’ll face the winner of Colorado State-Southern Utah in the second round.
With the loss, the Frogs finish their 2013-14 campaign with a 18-15 overall record. They also went 8-10 in conference play this season and held the Big 12’s top-scoring defense.