Halftime of the 2018 national championship game was ending, as Tua Tagovailoa was beginning his most anticipated run from the tunnel. After 30 minutes raced off the scoreboard, the quarterback headed back into the locker room — and an unrecognizable life.

Alabama’s rarely-used backup was eyeing a transfer when Nick Saban called on the true freshman to save a season, and turned Tagovailoa into a difficult-to-pronounce household name. He led the Crimson Tide back from a 13-point deficit against Georgia — throwing three touchdown passes upon being inserted at halftime, including the 41-yard game-winning overtime strike, which gave Alabama its fifth national championship in nine years.

“Everything changed,” Tagovailoa said one year later. “Just the way people look at you, the way people treat you, the family members. Everyone wants to be your cousin, too, now. Just social media, everything else changes. Your life is under a microscope now.”

The attention only increased the accolades.

Tagovailoa led the nation’s most dominant offense last year — throwing his first interception in November — en route to completing the most efficient season by a quarterback in the sport’s history. The Heisman belonged to the Hawaii native until a pair of ankle injuries forced him from the SEC title game.

When his second national championship game was through, Tagovailoa returned to another locker room, unfamiliar with the life before him.

The undefeated, top-ranked Crimson Tide’s second-quarter lead over Clemson somehow spiraled into the worst loss of Saban’s 12-year tenure (44-16). An offense that averaged over 45 points went scoreless for nearly three quarters. The Alabama quarterback threw as many interceptions (two) as he had in the entire regular season. A new true freshman, Trevor Lawrence, shoved Tagovailoa from the pedestal belonging to the best player in the nation.

“I think that he has to challenge himself to get back into great shape and overcome some of the things that happened toward the end of the year,” Saban said this offseason. “I think he should take the perception that he has a lot to prove, relative to how we ended the season.”

The perfect rival is in place to prove himself against.

Representing the powerhouse programs that have split the past four national championships, Tagovailoa and Lawrence again lead the top two teams in the nation, likely to embark on a season-long battle for the Heisman Trophy and another championship ring.

Lawrence, viewed as the best prospect since Andrew Luck or Peyton Manning, is a near-lock to be the No. 1 pick in the 2021 NFL Draft.

Tagovailoa is the front-runner to be first off the board in 2020. Either would have been the most coveted player this past spring, if draft eligible.

“It’s pretty rare. The only thing I can really draw comparable to is Vince Young and Matt Leinart, when it was pretty obvious they were on a collision course in 2005, but they really only intersected on one occasion,” said ESPN analyst Greg McElroy, the quarterback who led Saban’s Alabama dynasty to its first title in 2010. “These are two guys that are bona fide first-overall picks. … The fact that these guys see each other, that pushes them. There’s no denying that the Heisman Trophy is on both of their minds. They’ll say it’s not — Everyone is like, ‘Oh, I’m not worried about that’ — but you’re human. To think that the Heisman Trophy is within reach, how can that not be a driving force?”

To think that a uniquely gifted Tagovailoa, a 6-foot-1 Samoan southpaw, could look so much like a Lawrence, a 6-foot-6 golden-haired, golden-armed generational phenom.

Lawrence finished high school with two state championships, while becoming Georgia’s all-time leading passer and the top-rated recruit in the country. Tagovailoa finished high school with a state championship, while becoming Hawaii’s all-time leading passer and the top-rated dual threat quarterback in the country.

Less than a year after Saban plucked Tagovailoa from the bench, Clemson coach Dabo Swinney tapped Lawrence to replace Kelly Bryant — who led Clemson to the previous playoff — in the season’s fifth game. The 19-year-old Lawrence then exceeded his own hype, throwing 30 touchdowns and four interceptions while becoming the first true freshman starting quarterback to lead his team to a national title since 1985, torching Alabama for 347 yards and three touchdowns in the title game.

Either could become just the third quarterback since World War II to complete a rare trifecta — win a national championship, a Heisman and be the No. 1 pick in the NFL draft.

“They’re pretty special to watch,” McElroy said. “There’s been some criticism towards Tua, and I’m not really sure it’s fair. We have a tendency in life and in sports to be prisoners of the moment. If you look at the bigger picture, he was pretty sensational. No one right now has said anything negative about Trevor Lawrence. He’s spectacular — measurables, intangibles, natural ability. I would take Trevor [No.] 1 and Tua 2, but I don’t think the gap is as wide as everyone else makes it out to be. If you choose Tua first, I don’t have a problem with that.”

Lawrence is the popular Heisman pick — as Tagovailoa was last year — but just one of the past 13 preseason favorites has taken home the trophy.

“I think that’s kind of dangerous to start talking about all of that kind of stuff, even joking,” Lawrence said last month. “We kind of stay away from all of that and just go to work. … I don’t think it’s that hard to ignore it anymore. … That’s like anything. It’ll all played out.”

Last season, it played out with Lawrence leading Clemson to the first 15-0 season in FBS history and Tagovailoa suffering his first loss in college.

But the previous two times Alabama and Clemson each fell short of a national championship — due to a loss to the other — the loser won it the next year.

“National championship [defeat] was probably one of the biggest things I had to face, you know?” Tagovailoa said at SEC Media Day. “No one wants to go back and look at their mistakes … [but] I am glad I had that opportunity to feel a loss like that, because what can you learn from winning? You can’t learn as much. But when you lose, you start appreciating things a lot more, definitely in a different perspective as well.

“We’re all looking forward to having another shot at playing in the national championship and hopefully winning one, but we’ll just have to see.”