We are zipping through our preseason countdown of the top 25 players in the Big Ten for the 2013 season. This list is based on past performance and potential for the upcoming season only. We do not consider NFL potential for purposes of these rankings.

Our countdown reaches the teens today with a guy who holds great importance on and off the field for the preseason league favorite ...

No. 19: Jack Mewhort, OT, Ohio State, senior, 6-foot-7, 308 pounds

2012 postseason ranking: Not ranked

2012 numbers: Started all 12 games at left tackle for the Buckeyes. Was named second-team all-conference by league media.

Why he's here: Many people say left tackle is one of the most important positions on the field, and Ohio State went 12-0 last year with Mewhort as its left tackle, so that tells you a lot.

After starting at both left and right guard as a sophomore, Mewhort moved over to protect Braxton Miller's blind side last season and thrived in the job. The Buckeyes led the Big Ten in scoring and finished 10th nationally in rushing yards per game.

Mewhort enters this season as one of the top tackles in the Big Ten and the nation, and that's not all he brings to the team. Head coach Urban Meyer has pointed to his senior offensive lineman as the most likely heir to John Simon's role as the heart and soul of the team. He's already considered one of the Buckeyes' top leaders and should be a captain in 2013. Miller will be happy to see big No. 74 protecting him once again.

The countdown

No. 25: Jonathan Brown, LB, Illinois

No. 24: Mark Weisman, RB, Iowa

No. 23: James White, RB, Wisconsin

No. 22: Melvin Gordon, RB, Wisconsin

No. 21: John Urschel, G, Penn State

No. 20: Tyler Scott, DE, Northwestern