As the game wore on, the questions turned to clamor.

Where was Luke McCaffrey? Why wasn’t Nebraska using the redshirt freshman quarterback as it did against Ohio State? After an electric debut, the Colorado native was on the field for all of one play in the first half of Saturday's 21-13 loss to Northwestern.

Finally, he appeared. Late in the third quarter, McCaffrey took over behind center in place of Adrian Martinez.

He moved Nebraska’s offense through the air. He made a couple of plays with his legs.

But just like Martinez, he threw a crippling interception that ruined a scoring chance as the Huskers fell to 0-2. No matter who was taking the snaps, Nebraska seemingly refused to find ways to score in the red zone.

Still, the questions will become only louder as to who should get the majority of the snaps at quarterback as Nebraska turns its attention to Penn State.

"I don't really want to comment on that right now other than to say what I've said all along — I think we have two really good players," Nebraska coach Scott Frost said.

McCaffrey entered for good after Martinez’s throw across the middle to tight end Austin Allen was intercepted in the end zone. Martinez finished 12-of-27 passing for 125 yards and had a team-high 102 yards rushing on 13 carries.

McCaffrey, in his most extensive action at QB since last season, was 12-for-16 for 93 yards while running for 49 more.

"I feel for Adrian. That's a tough position to be in, and he's poured his heart and soul into this," Frost said. "But those guys are going to compete, and I'm comfortable with both of them in a game. I thought we needed a spark, and gave Luke a shot. He deserved it."

But the results were the same. Nebraska became the third consecutive opponent to go scoreless in the second half against Northwestern this season. McCaffrey’s interception came when a pass from the Northwestern 4-yard line appeared to glance off the helmet of offensive lineman Bryce Benhart and into the hands of the Wildcats’ Chris Bergin.

Needing to go 92 yards and then convert a two-point conversion just to tie the game, McCaffrey moved Nebraska to the Northwestern 14 before throwing incomplete to Wan’Dale Robinson in the end zone on fourth down.

Not all of Nebraska's shortcomings fall at the feet of those throwing the ball. Once again, Nebraska's lack of threats at the receiver position reared its head.

Outside of freshman Marcus Fleming, who broke out with five catches for 75 yards, Nebraska's other wide receivers combined for nine catches and 68 yards. Four of those catches and 32 of the yards belonged to Robinson.

Despite that, NU still averaged 5 yards per play on its 88 snaps.

"I trust both those quarterbacks equally. They’re both playmakers, they’re going to get things done. They obviously both have their skill sets. They bring something a little different to the table," said Allen, who had two grabs for 29 yards. "Adrian in there, Luke in there, I feel confident in both of them. There wasn’t necessarily a big mood change like, ‘Here we go, we’re going to do it now.' But Luke’s a competitor, Adrian’s a competitor, we competed, and that was my mentality toward it."

Mentality aside, the job of running Nebraska's offense appears to be as open as ever. And with an 0-2 team, in need of something positive, the intensity of that competition only escalates.