Tom Pennington/Getty Images
It's hard to argue Tony Jefferson is the best player on the Sooner defense. The junior free safety boasts a team-high 113 tackles this season. He has also logged two interceptions and has been critical in the secondary, especially in the most-recent win over TCU.
Jefferson is a superb tackler and thrives in big games, and his aggressive style of play will be one of OU's biggest assets against a high-end offense.
It's very likely Johnny Manziel will break into the second and third levels of the defense at least a couple times, and that could mean a one-on-one meeting between Manziel and Jefferson. Fans will be in for a treat if they see this confrontation.
Jefferson, like Harris, will be key for limiting the Aggie wideouts and preventing the deep ball. He will also be essential in run support and hitting Manziel sufficiently hard to make him think twice about running again. For Jefferson, and the defense generally, the No. 1 goal should be taking away Manziel's ability to run.
Manziel has averaged just shy of 100 yards rushing per game this season. In the Aggies' two losses, to Florida and LSU, he only ran for 60 and 27 yards, respectively. These represent his lowest outputs of the season.
In order for the Sooners to have a chance to win, they'll need to keep Manziel's run game under wraps. And Tony Jefferson, the star of the Sooners defense, will be integral in that effort.