Marcus Roberson, the nation's No. 9 safety and No. 112 overall prospect, commited to Texas Tech in January, but admitted he was only "50-50" committed to the Red Raiders.
This week, Tech fell on the wrong side of the coin flip after Roberson switched his commitment to Auburn, the reigning national champions. Roberson would have been the Red Raiders' highest-rated recruit.
Texas Tech hired Roberson's uncle this month, former defensive graduate assistant Otis Mounds, to coach cornerbacks.
Texas Tech's class is just outside ESPN's top 25, and Roberson's decommitment leaves the Red Raiders with 16 commits ready to sign today.
Texas A&M, meanwhile, beat out rival Texas for the commitment of Brandon Alexander, a 6-foot-5, 239-pound defensive end out of Brenham, Texas.
Alexander visited Texas in late January after making visits to TCU and A&M, and made later visits to Arkansas and Baylor, but elected to sign with Mike Sherman and the Aggies.
ESPN ranks Alexander as the nation's No. 32 defensive end, and his commitment gives Texas A&M 20 commitments for its 2011 class.