Crimson Countdown: LB Frank Shannon

During the summer, ESPN.com is taking a closer look at each scholarship player on Oklahoma’s roster in our Crimson Countdown series. Each day, we analyze each player’s impact on the program since arriving on campus, his potential impact this fall, and his long-term projection. Starting with No. 1 Dominique Alexander, the series follows the roster numerically through No. 98 Chuka Ndulue.

No. 20 Frank Shannon, linebacker 6-foot-1, 234 pounds, junior

Impact thus far: Shannon has been a solid contributor during his first two seasons on the field after a redshirt year in 2011. As a redshirt freshman, Shannon played in 12 games (two starts) and finished with 40 tackles including 3.5 tackles for loss, two sacks and one fumble recovery in 2012. ... In 2013, Shannon started all 13 games and was critical for the Sooners defense, particularly after the loss of senior linebacker Corey Nelson. Shannon led the squad with 92 tackles including seven tackles for loss, two sacks, one interception and one forced fumble.

Impact in 2014: Shannon missed the end of the spring due to personal issues. But if he returns to good standing within the program, he could be a key contributor on the defense for the third straight season.

Long term upside: Shannon has been an impact player for the Sooners since his redshirt freshman season. With 132 career tackles before his junior season, Shannon could finish his career as one of the most productive linebackers during the Stoops era.

Evaluation grade for Shannon: B. The Sooners did a good job with their evaluation of Shannon, who has been an impact player since his redshirt freshman season. His instincts and toughness have been a valuable asset for the defense for the first couple of years.

Development grade for Shannon: A. As Shannon began to come on as a redshirt freshman, the Sooners began finding ways to get him on the field even though they had Nelson and Tom Wort as solid starters. Shannon rewarded them by becoming a quality backup and part time starter in 2012 and evolving into the squad's leading tackler in 2013.