Twenty-nine years ago, a Rutgers fan was too busy.

Rutgers was playing Arizona State, its second NCAA Tournament appearance in three years. But one Scarlet Knights fan just couldn’t make the trip to The Omni in Atlanta.

“I’ll go next year,” Al Sa, a season-ticket holder, remembers his friend Tom saying. “That was 1991.”

The assumption of Rutgers’ continued success didn’t seem absurd at the time, but it has turned out to be painfully inaccurate.

Nearly three decades have passed, various coaches have participated in a game of musical chairs, and the team has led a nomadic existence through four different conferences.

But somehow, Rutgers’ postseason absenteeism has remained ever-present for an entire generation of fans.

“You would think that by pure luck we would have made it,” said Michael Lerner, another season-ticket holder who graduated from the school in 1979.

That poor fortune has undoubtedly begun to shift this year. Approaching their Big Ten Tournament opener on Thursday in Indianapolis, the Scarlet Knights have won 20 games for the first time since the 2003-04 season and earned an AP Top-25 ranking during the season (24) for the first time in 41 years. Despite winning just two games outside of Piscataway (2-8 road, 0-2 neutral), most bracket predictions are pegging them as a No. 9 or No. 10 seed. And the Rutgers Athletic Center, known as one of college basketball’s loudest venues in its heyday, is a fortress once again.

The team posted a staggering 18-1 record at the RAC, with its most recent home win (over No. 9 Maryland) bringing it to the precipice of a generational moment for the team’s young student-athletes.

“They weren’t even born [when Rutgers last made the tournament],” head coach Steve Pikiell said.

Pikiell is the Knights’ seventh coach since their last tourney berth, already more successful than most of his predecessors, but still shouldering the same heavy hopes of a return to the Big Dance. He can’t change the school’s decision to initially spurn the Big East (it didn’t join the conference until 1995), or erase from history the purgatory the program has endured since 1991.

But he knew the tournament-starved climate he was walking into when he took the job back in 2016.

“Since I’ve been here, it’s all that people talk about,” Pikiell told The Post.

A comedy of errors had consigned Rutgers to the cellar of college basketball before his arrival. Eddie Jordan couldn’t return the school to the glory of its 1976 Final Four run, Mike Rice Jr. got himself fired by abusing players (on camera) and Kevin Bannon burned any goodwill he had from two NIT appearances by forcing a game of “strip free throws” onto his players.

Unsurprisingly, ticket sales plummeted at the RAC.

“It was literally a morgue there for many, many years,” Lerner said.

That has now changed with the Scarlet Knights seemingly near-locks for the tournament. Beating Michigan on Thursday in Indianapolis would assuage any understandable anxiety from fans surrounding RU’s tournament hopes.

Fans who were alive for the Final Four run have lived a strange existence: old enough to remember the team’s heights from the 70s to the 90s, and young enough to have lived through a litany of painful Selection Sundays thereafter. What happens to your standards when they haven’t been met in decades?

For Sa, a Class of 1985 alumnus, the answer will be clear if Rutgers hears its name called this weekend.

“It’s not as if I’m going to sit back and rejoice … it’s where I expect us to be,” he said.