Important final season for Hicks, White

The 2014 season could be a critical one for several Big 12 seniors.

It’s their final chance to maximize their potential, show off for NFL scouts and push their teams to higher heights. In other words, it’s now or never for several Big 12 players who are poised to play the final 12 games of their college careers. Last week we looked at five offensive players who are facing now-or-never seasons. Here’s a look at five seniors on the defensive side of the ball who could have a major impact on their teams' success or hamper those chances for success if they struggle as individuals.

Linebacker Jordan Hicks, Texas

Why he might excel: Talent and production have never been the issue for Hicks. He was poised to become a star until back-to-back season-ending injures derailed his junior and redshirt junior seasons. If he returns to full health and remains healthy, he should be one of the Big 12’s top defenders. The Ohio native had 40 tackles in four games in 2013. If he's productive and healthy, Texas' defense is better and more experienced.

Why he might struggle: Much like teammate David Ash, Hicks' injury history makes it tough to build around him. Hicks has played in seven games in the past two seasons, with a hip injury in 2012 and a Achilles injury in 2013. There’s no guarantee he can return to be the active, productive player who was donned the burnt orange No. 3 during the past few seasons.

Cornerback Kevin White, TCU

Why he might excel: White has quietly performed at a high level for the past two seasons but has remained relatively unnoticed while being overshadowed by the excellence of fellow cornerback Jason Verrett, the San Diego Chargers’ 2014 first-round draft pick. White has started in 24 games in the past two seasons and earned honorable mention All-Big 12 honors as a junior. His senior season offers a chance for him to cement himself as one of the top defenders in the conference, particularly as TCU’s top cover man.

Why he might struggle: He will be asked to be the man in the secondary. While lining up opposite Verrett, White was tested plenty during the past two seasons. But can he hold his own when consistently asked to cover the Big 12’s top receivers? If he stumbles, there aren't a lot of experienced options to turn to in the Horned Frogs' secondary.

Defensive tackle James Castleman, Oklahoma State

Why he might excel: Castleman has been productive for the Cowboys during the past two seasons and has all-conference potential. This season is his last opportunity to fulfill that potential. He enters the season with 70 tackles, including 11.5 tackles for loss and two sacks in his first three seasons. If Castleman is a disruptive force in the middle, he would help the Cowboys' inexperienced secondary greatly.

Why he might struggle: Castleman has seemed like a guy who could have a breakout season since his sophomore year. Yet it hasn’t really happened during his first three seasons. With Calvin Barnett moving on, Oklahoma State will lean on Castleman to fill the void and take his game to another level. He has supreme talent, but needs to finally maximize his potential during his final season.

Defensive end Geneo Grissom, Oklahoma

Why he might excel: He’s an NFL-level talent with unique physical gifts. Grissom finally began to show his ability to be a dominant player in the final stretch of the 2013 season, particularly the Allstate Sugar Bowl victory over Alabama. His junior season was easily his most productive with 40 tackles, including nine tackles for loss, 4.5 sacks, two fumble recoveries and an interception. The Sooners clearly view him as a critical piece in the defense and he could be a guy who helps Eric Striker and Charles Tapper create havoc for opponents.

Why he might struggle: Grissom’s exceptional athleticism has been an anchor during his career in some ways. Recruited as a defensive end, Grissom moved to tight end at one point during his career and he even practiced at linebacker during the spring. The constant moving might be one reason for inconsistency in his play. If he consistently plays his best football, he can be an All-Big 12 performer and rise up NFL draft boards. If he doesn't maintain his Cotton Bowl production, Oklahoma's defense would take a step backward.

Linebacker Kenny Williams, Texas Tech

Why he might excel: He’s a terrific team player and is very versatile. He’s proved he can be a quality Big 12 running back and appears poised to start at linebacker during his final season at Texas Tech. Williams has a unique ability to play several roles and make an impact. If he can excel at linebacker, it gives the Red Raiders a little more piece of mind about a defense that will have to improve greatly for Tech to make a Big 12 title run.

Why he might struggle: He’s listed as a starter at a position he hasn’t called home during his time as a Red Raider. He enters the season as Tech’s most productive returning running back, but his move to linebacker is the best move for the team. It could take him a while to adjust and become productive.