LINCOLN, Neb. (AP) -- - Nebraska defensive coordinator John Papuchis is counting on seeing improvement from his group for Week 2.
"We have nowhere to go but up,'' Papuchis said. "I assume that's going to be the case for us.''
The No. 22 Cornhuskers won their opener 37-34 over Wyoming last week.
But it seemed like a hollow victory to players and coaches after they allowed 602 yards to a team that lost eight of 12 games in 2012. That was also reflected in the Top 25, as Nebraska dropped four spots.
It was the second-most yards the Huskers had allowed in a win. The most was 610 yards to Ball State in 2007.
Nebraska faces a second straight spread offense Saturday night in Southern Mississippi, which lost its opener 22-15 to Texas State in Todd Monken's first game as head coach.
The Golden Eagles will come to Lincoln on a 13-game losing streak, longest in the FBS.
Southern Miss' offense scuffled against Texas State, committing six turnovers and rushing for just 23 yards. But Allan Bridgford, who transferred from Cal for his final season, threw for 377 yards.
Nebraska defensive tackle Vincent Valentine said he anticipates a rugged week of practice.
"It's definitely going to get crazy,'' he said. "There's going to be stress. We have to prepare better. We have to come out way better against Southern Miss.''
Papuchis came into the season knowing it would take time for the defense to improve.
Only three of his players, end Jason Ankrah and cornerbacks Ciante Evans and Josh Mitchell, had started more than half the games last year.
Four true freshmen, two redshirt freshmen and one junior college transfer had their first action on defense, as did converted offensive lineman Brodrick Nickens.
"The hardest thing when you have new guys isn't that you feel like they're going to make mistakes on things you practice,'' Papuchis said.
"It's making adjustments and handling them. It's an opening game, and anything (Wyoming) put in in the offseason, we're totally unaware of. A critical element is to make fast adjustments. We made the corrections. Getting them translated was a bit of a struggle.''
Papuchis said Wyoming capitalized on the Huskers' inability to get players in the right spots to defend the quarterback run. Wyoming's Brett Smith had 92 yards rushing in addition to 383 yards passing.
The Huskers also failed to sustain pressure on Smith, though much of that had to do with his ability to escape trouble.
Still, Nebraska had no sacks. Randy Gregory appeared to have a sack, but he was called for roughing the passer.
The tendency to allow big plays, which hurt the Huskers last year in the Big Ten championship game against Wisconsin and in a bowl loss to Georgia, was evident again.
Wyoming had eight plays that went for more than 20 yards, four of them in the fourth quarter as the Cowboys trimmed a 16-point deficit to three.
"I thought we came out and did some better things to start the third quarter,'' Papuchis said. "At times we made some progress, and we collapsed at the end. Whether we let up, whatever the reason was, I can't quite answer that now. We gave up big plays at the end and it's disappointing.''
Cornerback Stanley Jean-Baptiste said the Huskers' demeanor changed after they got ahead by two touchdowns.
Lesson learned, he said.
"We just got more relaxed,'' Jean-Baptiste said. "On the sideline we kept playing around and weren't taking everything seriously. We just lost focus and they battled back.''
Nebraska might feel more confident about its offense this week, as quarterback Taylor Martinez says his left shoulder is fine and he'll be at full strength.
Martinez injured the non-throwing shoulder in the third quarter Saturday, but coach Bo Pelini described the injury as a bruise.
"We're not going to hit him in practice. We never do,'' Pelini said. "As far as what he can do, he'll be out there and he'll be fine. It's nothing that will restrict him.''
Martinez was 17 of 22 for 155 yards and three touchdowns, and ran 16 times for 80 yards as Nebraska rolled up 375 yards on the ground. However, he was intercepted and fumbled on consecutive series in the fourth quarter, and Wyoming converted both turnovers into touchdowns to make it a three-point game.
"I think we weren't very happy with ourselves when we let them come back into the game, and that shouldn't have happened,'' Martinez said. "Great teams don't let that happen.''
Martinez was considerably better in the most recent meeting between Nebraska and Southern Miss, a 49-20 Huskers home victory last Sept. 1. He was 26 of 34 for 354 yards, five touchdowns and no interceptions.