A whirlwind of Big-12 and College Football Playoff possibilities descends upon the No. 5 Oklahoma Sooners and No. 9 Oklahoma State Cowboys when they wrap up the regular season in Saturday’s mega-clash at Boone Pickens Stadium in Stillwater.

The Sooners climbed two spots in the latest Associated Press Top 25 poll for their highest ranking of the season following 30-29 nail-biter over then-No. 18 TCU despite quarterback Baker Mayfield sitting out the second-half with a concussion.

Oklahoma State, however, suffered its first defeat of the season after riding a 10-game winning streak and fell to then-No. 10 Baylor 45-35. The loss resulted in a 10 spot slide in the AP Poll, and the Cowboys will likely slip away from the sixth spot when the latest CFP rankings are released Tuesday night.

But thanks to Oklahoma’s consecutive wins over Baylor and TCU, and the lack of a conference championship game, the Sooners and Cowboys will now decide the Big-12’s champion.

Oklahoma and head coach Bob Stoops rose five spots to seventh in the CFP rankings and with Ohio State and the Cowboys losing they could take over the fifth spot while hoping for Notre Dame or undefeated Iowa to lose their regular season finales to sneak in as the Big-12’s lone rep in the national title tournament.

The Sooners certainly have a case that doesn’t strictly hinge on their wins over the Bears and Horned Frogs. They’ve toppled four ranked teams this season and the Cowboys would be the fifth if they prove successful, but any of the scenarios that allow Oklahoma a shot at the national title rest on the health of Mayfield.

According to NewsOk.com, the Heisman Trophy candidate was kept out of the second half against TCU more as a precaution since he passed concession tests. The report also stresses that Oklahoma’s medical staff will keep a close on Mayfield but that “signs so far appear good” for him to play against the Cowboys.

The junior’s been sensational for the Sooners all season and his absence left the offense struggling against the Horned Frogs. Mayfield’s completed 68.7 percent of his passes for 3,209 yards and 33 touchdowns to only five interceptions, including the 23-7 lead he gave Oklahoma before halftime and his eventual benching.

Oklahoma inserted Trevor Knight in Mayfield’s place and the offense sputtered while the defense clung to the lead. With Knight under center the Sooners punted on six of their nine drives in the second half, and running back Samaje Perine’s 72-yard touchdown burst and the Horned Frogs failed two-point conversion in the final minute of play saved Oklahoma’s season.

The Cowboys chances of making any further noise in the CFP will hinge on their success against Oklahoma and the bevy of teams in front of them in the rankings. Oklahoma State will need Clemson, Alabama, Iowa, Notre Dame, and possibly Michigan State to lose for any traction in the CFP rankings.

But they certainly have the firepower to upend the Sooners hopes. Standing as the fourth most-efficient passer in the conference, quarterback Mason Rudolph fired off three touchdowns and the Cowboys compiled 441 total offensive yards against the Bears. Despite the loss Oklahoma State still owns the nation’s sixth-highest scoring attack with 42 points per game.

Betting Line: Oklahoma -4

Prediction: Oklahoma over Oklahoma State, 40-30