Jermie Calhoun came to Oklahoma as the nation's No. 1 running back and the No. 7 overall recruit in the Class of 2008's ESPNU 150.
Stuck on the back end of the depth chart, Calhoun has become the second Oklahoma running back to transfer since the season began.
Jonathan Miller also announced his transfer earlier this month.
Both players plan on staying at Oklahoma through the semester.
"We understand Jermie wants an opportunity to play more. He has our support and best wishes," coach Bob Stoops said in a release.
Calhoun rushed for 220 yards and a touchdown on 45 carries as a freshman in 2009, but got just 11 carries in 2010 before suffering a serious knee injury against Colorado.
The Van, Texas native has been unable to crack the depth chart this season with two sophomore backs, Brennan Clay and Roy Finch, emerging, as well as walk-on Dominique Whaley, who rushed for four touchdowns and 131 yards in Oklahoma's season opener.
Calhoun's decision means the nation's top two running backs in the 2008 class both signed with Big 12 schools before eventually transferring. Colorado signed Darrell Scott from that class, but he transferred to South Florida after the 2009 season.
Here's how the rest of the ESPNU 150 Big 12 signees from 2008 have done throughout their careers.