It just flared up and was not a result of any contact, said sports information director Kenny Mossman.
OU head coach Bob Stoops was not available for comment about the issue.
As a result, redshirt freshman Tom Wort, who was already listed as the starter on the latest depth chart, figures to be the starter.
More information will be posted on the matter as soon as it becomes available.
Stay tuned also for a write-up on Wort, who said he's ready to step up.