Texas Tech coach Mike Leach talks with an official in the second quarter of the Red Raiders' 49-45 loss to Oklahoma State. The teams kicked off the Big 12 Conference season Saturday in Stillwater, Okla.

Get meaner and nastier.

That was the message Texas Tech coach Mike Leach had for his defense after the Red Raiders’ 49-45 loss to Oklahoma State on Saturday.

“The defense can’t sit there and pout,” Leach said. “They need work on having a burning desire to be tougher than the guy across from them.”

The Red Raiders will have to do that with a new defensive coordinator after Lyle Setencich stepped down Sunday, citing personal reasons.

Leach named assistant head coach Ruffin McNeill as the interim defensive coordinator.

There were plenty of coaches around the Big 12 with stern words for their defenses after Week 4. Iowa State surrendered 36 as the Cyclones were beaten by Toledo. Texas A&M was torched for 34 points in a loss to Miami, knocking the Aggies out of the poll. No. 25 Nebraska gave up 40 points in a narrow win at home against Ball State.

“It’s obvious that we have to amend some things,” said Nebraska coach Bill Callahan, whose defense gave up 610 yards of total offense to the Cardinals, the fourth-most ever against the Cornhuskers. “But overall our defense made some plays at the end to win this football game.”

The Cornhuskers gave up 49 points to top-ranked USC the week before. However, Callahan isn’t fretting about his defense.

“I think it was a completely different game than it was last game,” Callahan said.

There were some standout defensive performances as well. Colorado limited Miami (Ohio) to 139 yards of total offense and six first downs in a 42-0 rout. It was the first time since 1993 the RedHawks have been shut out.

“We kept it rolling and got the zero,” Buffaloes defensive tackle George Hypolite said.

The third-ranked Oklahoma Sooners turned in a businesslike performance in a 62-21 win over Tulsa, rolling up 553 yards of total offense.

Tulsa may have been the Sooners’ sternest exam so far this season. Oklahoma had given up just 26 combined points in its three previous games.

“Tulsa runs a very unconventional offense,” Sooners coach Bob Stoops said. “It requires discipline and I think our guys are better that they went through it.”

The seventh-ranked Texas Longhorns had little difficulty with Rice, winning 58-14, and No. 20 Missouri breezed past Illinois State, 38-17. Baylor also beat Buffalo, 34-21, running the Big 12’s record for the week to 8-3, with Kansas State having a bye.

Missouri coach Gary Pinkel said the Tigers still had work to do, despite racking up 581 total yards on offense.

“I don’t think we’ve come close to playing our best game yet, and that’s good,” Pinkel said.

Red Raiders quarterback Graham Harrell found it hard to believe the offense scored 45 points and still lost.

“It’s always frustrating when you fail,” said Harrell, who threw for a career-best 646 yards passing. “We definitely thought we could have won the game, and we let it slip away.”

Actually, it bounded away, off the hands of Michael Crabtree, the nation’s leader in receptions. Crabtree let a 15-yard pass hit off him and fall to the ground with 11 seconds remaining.

Leach said he didn’t try to console Crabtree after the game.

“We don’t have time to pout,” he said. “I’m not putting up with pouters. We’ve got to fix it and become the best team that we can and play a full 60 minutes.”