Devin Davis, Oklahoma State's projected starter at left tackle, tore an ACL and is probably out for the season, Gina Mizell of The Oklahoman reports.
Davis started two games in 2012. The No. 13 Cowboys entered the season already needing to replace last year's starting center and each guard, all gone to graduation.
Oklahoma State has been in the top five nationally in scoring offense each of the last three seasons and is projected by the media to win the Big 12 conference. The Cowboys open the season Saturday against Mississippi State in Houston.