How the redshirt freshman backup came off the bench and electrified the college football world on Saturday.

AUSTIN, Texas — Rarely do sideline celebrations get lost enough in the fog of competition that film review is necessary to determine what exactly happened, but that’s precisely what Texas Longhorns redshirt freshman quarterback Arch Manning thought was necessary in the aftermath of scoring five touchdowns in the 56-7 victory over the UTSA Roadrunners on Saturday night at Darrell K Royal-Texas Memorial Stadium.

“I don’t know what happened,” Manning admitted.

Minutes earlier, Texas head coach Steve Sarkisian had joked about what transpired when Manning came off the field after a touchdown.

“I think he tried to headbutt me,” Sarkisian said. “I think I might have dodged him.”

Manning couldn’t rule out the possibility.

“Yeah, in the moment, maybe,” Manning said.

The rest of Manning’s performance, the most extended action of his young career coming after starting quarterback Quinn Ewers suffered an abdominal strain early in the second quarter and did not return, doesn’t require much film review to understand — Manning was simply phenomenal in going 9-of-12 passing for 223 yards and four touchdowns and ripping off a 67-yard touchdown run on a rare zone read call by Sarkisian.

“We take a lot of pride in our practices and being competitive and going good on good, things of that nature, to try to make as many game-like situations as we can. But there’s nothing like being in the game and playing in front of 105,000 people is not the easiest thing to do. So I was really proud of Arch and what he was able to do,” Sarkisian said.

Manning didn’t waste any time making a positive impact, finding sophomore wide receiver DeAndre Moore Jr. for a 19-yard touchdown on his first pass attempt, rolling right after a run fake and quickly getting to his third read to target Moore.

Manning’s third play from scrimmage was perhaps his most sensational of the night, pulling a zone read, putting a move on a safety, and then hitting 20.7 miles per hour on his way to the end zone for the longest run a Texas quarterback since Vince Young ripped off an 80-yard run against Oklahoma State in 2005 to spur a comeback in Stillwater.

“When the adrenaline kicks in, it helps you run a little bit faster, but I credit that to Torre Becton, our head weight coach — he runs our tails off in the summer, so I think I’ve gotten a little bit faster since I’ve gotten on campus,” Manning said.

Where does that athleticism come from? It certainly passed over his famous uncles.

Sarkisian credited Arch’s grandfather, his namesake Archie Manning, the legendary quarterback at Ole Miss and for the New Orleans Saints. Manning himself also shouted out his mother Ellen, a volleyball and track standout at Sacred Heart in New Orleans in the late 1980s.

The two plays showcased areas where Manning shines — throwing on the move in either direction, a skill honed by necessity in high school when he played behind a porous offensive line, and in the occasional quarterback run game, a changeup for the Longhorns under Sarkisian.

“Well, it’s different, right?” Sarkisian said of the quarterback run game.

“It’s not something that we’ve done a ton of here. We did a little bit back in the day with Hudson [Card] when we had him, and so to have that at our disposal, sometimes it can keep people a little bit more honest. But we’re never going to major in that — that’s not who we are philosophically as an offense — but we like to have that in our back pocket to keep keep things honest.”

A 51-yard touchdown pass to junior wide receiver Isaiah Bond was simple enough for Manning — he flipped the ball out to the Alabama transfer on the perimeter and Bond’s speed did the rest with the help of two perimeter blocks.

And freshman wide receiver Ryan Wingo was cut loose by the UTSA defense on a shot play that went for 75 yards, although Manning did show some poise and toughness in the pocket, taking a hit as he delivered the football.

A better throw was a 36-yard gain to Wingo that saw Manning hit a small window in connecting with the St. Louis product while rolling left, a remarkable throw across his body.

It’s a connection Manning and Wingo have been able to foster in practice since Wingo’s arrival as an early enrollee in January thanks to the team’s depth at wide receiver.

“I get more reps with Wingo practice and he’s the man. What a good guy. I mean, he’s going to catch a lot of touchdowns here — this sky’s the limit for him,” Manning said.

The practice rotation at wide receiver isn’t the only area of preparation that helped Manning on Saturday. The night before games, Sarkisian meets with his quarterbacks and goes through the call sheet, allowing each to pick their favorite plays based on situation, like base, third down, and red zone.

“We mark those down and so if the backup goes in like Arch, we knew the plays that he picked, that he liked, and went into this game plan. So it makes life a little bit easier for us — we try not to be stubborn and just call what we think is the best play, because ultimately, they’re the ones that have to execute them,” Sarkisian said.

But even with the set of plays that Manning picked based on his comfort level, there’s a level of mental and physical preparation that went into the redshirt freshman’s ability to execute at such a high level coming off the bench. It starts in practices under Sarkisian, where the backups practice the hardest concepts the Longhorns utilize to ensure they’re comfortable in the exact type of situation that Manning faced against the Roadrunners.

In that regard, one of the most heartening moments for Sarkisian came on Manning’s least successful play, a 10-yard sack on a 3rd and 5 from the Texas 26-yard line with around four minutes remaining in the second quarter.

“The sack we take on third down is a five-man protection,” Sarkisian said. “We didn’t do a great job with the clock management. Arch was ready to change the protection, but knew the clock was running down, had to get it snapped and ends up getting sacked on the play. He was able to come right off the field and verbalize all that to me in real time, which tells me he was clear-minded and focused on what we were trying to do.”

The clear-mindedness and focus is something that quarterbacks coach AJ Milwee hammers home for Manning repeatedly.

“Coach Millwee kind of instills that I’ve got to prepare and be ready every week for when my number’s called and help this team win games and that’s what I tried to do tonight,” Manning said. “Obviously, there’s a lot to improve on and grow from, but I’m glad I got to get in there and get hit again and feel what it’s like.”

If there is truly a lot for Manning to improve upon after such an impressive performance.

Well, that’s a scary thing for the rest of college football to consider in the short term and the long term.