Who are the 10 biggest X factors in the Big 12?

For Texas' shaky passing game to improve in 2016, the Longhorns will need a big step forward from John Burt, who had 28 catches for 457 yards and two touchdowns last season. John Rivera/Icon Sportswire

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Most of the attention toward the Big 12 will, rightly, revolve around the star power of Baker Mayfield, Mason Rudolph and Malik Jefferson.

But even the best players in the Big 12 need some help, perhaps from unexpected places. Here's a look at the league's 10 most critical X factors.

Oklahoma Sooners: WR Geno Lewis

Four years ago, Justin Brown transferred in from Penn State to boost Oklahoma's receiving corps. Now the Sooners hope another former Nittany Lion can do the same. Lewis needs to regain his form; he caught 55 passes in 2014, then just 17 last season. But on a unit that graduated All-American Sterling Shepard (86 catches, 1,288 yards, 11 TDs) and returns just one pass-catcher with more than 28 receptions (Dede Westbrook, 46), any newcomer is good news.

Oklahoma State Cowboys: DT Vincent Taylor

Taylor will take on a bigger role after a sophomore season that included 48 tackles, 8.5 tackles for loss and five sacks. The 6-3, 310-pounder had five games with at least five tackles. But he won't have Ogbah, who led the Big 12 in sacks, drawing attention on the outside, meaning Taylor will become the focus of opposing offenses for the first time in his career.

Baylor Bears: LB/DB Travon Blanchard

Blanchard should be the defense's top returning playmaker. The junior's tendency to rise to the occasion in big games (29 combined tackles against Oklahoma, Oklahoma State and TCU) could be a key asset for a unit that is a relative unknown. Blanchard's abilities against both the run and the pass make him an ideal hybrid defender in the Big 12.

West Virginia Mountaineers: DE Noble Nwachukwu

Nwachukwu's name rarely comes up when debating the Big 12's top defenders, but he finished his junior season with 8.5 sacks and 13 tackles for loss, tied for fourth and 10th, respectively, in the conference. The 6-foot-2, 275-pound senior registered all but one of his sacks against conference opponents, including three in a 38-20 win against Texas.

Texas Longhorns: WR John Burt

Last season Texas didn't have a single pass-catcher finish in the top 20 in the Big 12 in receiving. But as the Longhorns transition into a version of the Baylor offense under new coordinator Sterlin Gilbert, they will have to find a standout receiver or two to make the attack work. One option will be 6-foot-3 sophomore Burt, a former ESPN 300 signee who led Texas with 457 receiving yards last season as a true freshman.

TCU Horned Frogs: DE James McFarland

McFarland entered the offseason a forgotten man after missing 2015 with a broken toe suffered when he stepped on a sprinkler head. But the defensive MVP of the 2014 Chick-fil-A Peach Bowl is set to provide pass-rushing punch for a Horned Frogs defense that needs to be much improved. McFarland had seven sacks and three forced fumbles in 2014. Last season TCU finished fifth in the Big 12 with 32 sacks. With three other injured players now healthy, the defense could return 11 vets with starting experience.

Texas Tech Red Raiders: DT Breiden Fehoko

Last season the defense allowed 279.9 rushing yards per game, ranking 126th in the nation, ahead of only Eastern Michigan. The Red Raiders have been searching for an impact player on the defensive line whom they can build around, and they might finally have found him in Fehoko, a 6-foot-3, 295-pound sophomore. The prized recruit (No. 51 in the ESPN 300) started every game at defensive tackle as a true freshman last year and will have the benefit of playing with two eligible transfers, DT Ondre Pipkins (Michigan) and LB Kolin Hill (Notre Dame).

Kansas State Wildcats: S Dante Barnett

The MVP and glue of K-State's defense two years ago, Barnett is back after missing virtually all of last season with a shoulder injury. Barnett, who has started 29 career games, has a nose for the ball, resulting in seven career interceptions. If he can rediscover his form of two seasons ago, K-State will have a chance to be far more opportunistic defensively after finishing tied for last in the Big 12 in 2015 with just five picks.

Iowa State Cyclones: DB Kamari Cotton Moya

In 2014, Cotton-Moya was the Big 12 Defensive Freshman of the Year. Last season, however, he missed Iowa State's final six games with a hamstring injury after registering 40 tackles in the first six games. If he remains healthy, the Cyclones could feature one of the top defensive backfields in the Big 12, with proven cornerbacks Nigel Tribune, Jomal Wiltz and Brian Peavy flanking him.

Kansas Jayhawks: WR LaQuvionte Gonzalez

The junior receiver, a 5-10, 176-pound transfer from Texas A&M with 4.4 speed and a 41-inch vertical, could provide a big-play threat. Kansas coach David Beaty was his position coach at A&M and promises to get creative with Gonzalez to get him the ball in as many ways as possible. In 16 games with the Aggies, he had 26 catches for 317 yards and two touchdowns.