If he had any nerves, he didn't show them.

Andrew Bunch grabbed his helmet, picked up a football and started warming up just seconds after starting quarterback Adrian Martinez went down with a leg injury late in the fourth quarter Saturday against Colorado.

There was no hesitation, and no sign of panic from the walk-on sophomore after he entered with 3:29 left in Nebraska's 33-28 loss.

It was just like he expected. Although he wasn't expecting an injury to knock out starter Adrian Martinez in the season opener.

"That's what I've been waiting for (the chance to play)," Bunch said Saturday evening. "We practice situational football all the time, so when it comes up, it's nothing new. It's just another experience."

[ WATCH: Bunch talks about his performance against Colorado ]

Nebraska's coaches, throughout the spring and into the fall, have praised the lightly recruited Bunch's ability to run NU's offense. The Thompson Station, Tennessee, native showed what those coaches were talking about on his first series, rifling a pass to JD Spielman on the sideline that was on the receiver's hands before being juggled and dropped.

And when Nebraska needed a touchdown in the game's dying moments, Bunch led the Husker offense onto the field with 1:03 left and immediately completed a 14-yard pass to Mike Williams to get NU going.

Williams said his message to Bunch when he entered was simple.

"It's your team now," Williams said he told Bunch. "We've got you. We've got your back."

Bunch ran a spread offense in high school, throwing for nearly 8,000 yards and 79 touchdowns and rushing for 1,140 yards in his three-year career as a starter. He won a state championship as a senior, throwing for 3,405 yards and running for 520 more.

After one season at Scottsdale Community College in Arizona, he saw an opportunity in Lincoln and walked on.

Now, suddenly, he was on the field in front of nearly 90,000 fans trying to engineer a miracle finish.

He and the Huskers came up short. A pass to an open Stanley Morgan in the end zone was a second or so too late. After a throw-away to stop to clock, two more throws from the Colorado 20-yard line went begging, including a last-gasp jump ball with Spielman and Stanley Morgan, two of NU's top playmakers, trying to make the catch.

"I wish we could have gotten the ball in the end zone on the last play. That's really what I'm thinking about (right now)," Bunch said. "But I think the team's going to have a short memory about it and get ready to work next week."

[ WATCH: Frost's postgame news conference following loss to CU ]

Bunch said he receives every play call on the sideline while the Huskers are on offense. From there, he explained, it's a matter of visualization and trying to make the proper read as if he was the one on the field.

And with Martinez's status unclear as Nebraska moves forward, Bunch said, don't expect a change in the way he goes about his business.

"I’m just going to treat it the same way I always have. I’ve always tried to prepare like I’m the starter, regardless of what position I’m in," Bunch said. "So I’m going to attack Monday the same way I always do."

Bunch is the second walk-on to get game snaps at quarterback for the Huskers in the last three seasons, joining Grand Island native Ryker Fyfe in 2016.

Whether he starts a game, as Fyfe did two years ago, remains to be seen.

[ PHOTOS: Huskers fall to Buffaloes in opener ]

Reach the writer at 402-473-7436 or cbasnett@journalstar.com. On Twitter @HuskerExtraCB.