NORMAN, Okla. -- Baker Mayfield doesn't want to hear it, but the Ohio State game is bigger than him or Oklahoma.

In the season's second week, it is, in fact, a must-win for the Big 12.

Yup, here we go again. The Power Five conference with the fewest appearances in the first three years of the College Football Playoff (one) is on the clock.

With a shaky first week in nonconference play and precious few top-notch matchups left, Oklahoma -- and the conference as a whole -- could be facing their playoff mortality Saturday night.

"I could care less," said Mayfield when asked about a must-win. "I love the Big 12 Conference. They gave me my extra year back. I'm trying to take care of Oklahoma." https://www.cbssports.com/college-football/news/big-12-changes-its-mind-and-reverses-walk-on-rule-helping-baker-mayfield/

OU's playoff chances faded last September with losses to Houston and Ohio State in the season's first three weeks. The Sooners' playoff anxiety increased as the season went on. OU won the Big 12, the rest of its games and still missed the playoff.

Meanwhile, the OU win was probably the difference in Ohio State becoming the first team not to win its conference get in the CFP.

At least one Ohio State player recognizes the enormity of Saturday night.

"It's a must-win game if we want to do what we want to do," Ohio State defensive end Nick Bosa said. "If we lose, we're going to play in a bowl game, but it's not going to be a run for the national championship."

The Big 12 already is playing catch-up in the playoff race. Conference teams lost the only two matchups against Power Five opponents last week: Virginia Tech over West Virginia and Maryland over Texas.

Baylor also lost at home to Liberty.

There is only one Big 12 nonconference game left with a currently-ranked opponent: Texas goes to USC on Sept. 16.

Starting to sense the desperation? The Big 12 is the only Power Five conference to miss the CFP twice. Missing it once caused the conference to go on a fruitless expansion search. The league eventually settled for a conference championship game beginning this year.

The Sooners believe they may be better prepared to beat the Buckeyes this time around. Their 11-game winning streak is the nation's longest. Mayfield is sharper, if that's possible. He completed his first 16 passes against Texas-El Paso before exiting at halftime.

An Ohio State secondary that lost three first-round draft choices seems vulnerable.

"There's a time when you face adversity and you go into a hostile environment. You go into your shell or come out and shine" Mayfield said. "Without pressure there's no diamonds."

That adversity hit last September when Oklahoma endured a rare home loss. The further tragedy would be the nation's longest winning streak being bracketed by losses to Ohio State.

"We've never been here for a team to sing a fight song on our field. Frankly, it's just embarrassing," Mayfield said of last year's 45-24 loss to the Buckeyes.

"O-H, I-O on our field. Their fans were louder than ours. Rightfully so. It's a different year. We're thinking about that. It hurts."