Three facts about Preston Rex's (No. 12) transition from defense to RB like Tyler Allgeier

The former safety has moved to running back in this his redshirt junior season. Can he be the next Tyler Allgeier after converting from tackling ball carriers to becoming one?
BYU v Oklahoma State
BYU v Oklahoma State | Brian Bahr/GettyImages

The BYU Cougars kick off the 2025 season in 12 days against Portland State. As we continue counting down the days until kickoff, today we will profile the player who wears No. 12 - redshirt junior running back Preston Rex - by providing three interesting, fun facts. (Note, that's Rex in the photo above wearing No. 27 but he has since changed his number to 12.)

Fun fact No. 1 - He's switching from safety to running back

Preston Rex joined the BYU Cougars as a safety on the defensive side of the ball. The redshirt junior has appeared in 12 games over three seasons with 17 total tackles and one pass defended. But this year Rex somewhat surprisingly changed position to running back as the Cougars have a ton of talent and depth in the secondary, but are surprisingly thin at running back after losing both Hinckley Ropati (personal) and Cale Breslin (transfer).

This may be Rex's first attempt at his new position. When he signed with BYU back in 2020 he was a safety first but could also reportedly play wide receiver. Former defensive-player-turned-running-back Tyler Allgeier is Exhibit A in how switching from tackling ball carriers to become one can be the right move.

Fun fact No. 2 - He's a BYU legacy guy

The Rex name is familiar to BYU football fans. Per Preston's player profile at BYU's website, his father, Byron, was an All-American tight end for the Cougars. His older brother, Isaac, was a standout tight end at BYU from 2019 to 2023. As Preston now moves to running back, his father and brother should give some indication that members of the Rex clan can succeed with the ball in their hands.

Fun fact No. 3 - He's a returned missionary

Preston served a mission for the Church of Jesus Christ of Latter-day Saints in Orsono, Chile and McAllen, Texas. He's a fluent Spanish speaker, plays the piano, and served as a Sunday School Teacher in his local congregation.

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