Dallas Mavericks head coach Rick Carlisle had never seen the American Airlines Center as crowded for player warm-ups as it was Tuesday night before a meaningless game between two teams already eliminated from the playoffs.

“That includes the Finals,” Carlisle said. “I don’t think we’ve ever had this many people here at 7:15 for a 7:40 tip-off.”

The Mavericks’ matchup against the Denver Nuggets was fan appreciation night, but that wasn’t the reason for the big turnout. A large contingent of the fans weren’t even wearing Maverick jerseys. They were wearing Dallas Cowboy jerseys.

In a gimmick that could be perceived as both cheesy and endearing, recently retired Cowboys quarterback Tony Romo joined the organization as a Maverick for the day. He participated in the team’s morning practice, suited up for the game, and was announced in the starting lineup.

The notion that Romo might actually enter the game as a 36-year old retired football player seemed a little far-fetched, but there was genuine excitement about watching him partake in the pregame layup line.

Jeremy Aragon, a Romo supporter who said he was “born into” his Cowboy fandom, bought premium tickets as soon as he heard the news. “I doubt he plays,” Aragon said pre-game in his Romo jersey. “But just to see him here and see the standing ovation he gets from the fans is going to be a cool experience.”

When the Mavericks finally ran out on the floor for warm-ups, Romo was with them. It’s no exaggeration to say that a sense of nervous anticipation came over the crowd when Romo received his first pass in the lay-up line. He dribbled forward, made a smooth behind-the-back move, and laid the ball in the hoop. The crowd erupted like something far more significant than the most routine basketball feat had just happened.

Mavericks’ star forward Dirk Nowitzki addressed the crowd and introduced Romo, who, embarrassed, exclaimed his love for the city before taking his seat on the bench for tip-off.

The arena became startlingly quiet once the ball tipped and the fans realized they were watching a game between two teams that had nothing at stake. A steady diet of Nowitzki jump shots kept the crowd engaged, but what likely kept most people in their seats was the fear of missing the tiniest chance that Romo would enter the game. Was it even possible? Maybe. This is the team owned by notorious headline-grabber Mark Cuban, after all.

Cuban had approached NBA commissioner Adam Silver with his idea earlier in the week. “I told him what I was going to do and I said, ‘Fine me if you don’t like it,’” Cuban said before the game with a smile.

Part of the Romo legend is that he was a terrific high school basketball player back in Wisconsin. Former Maverick Caron Butler was on Romo’s high school basketball team and told ESPN this week that Romo could have played professionally. Nowitzki took him on in a shooting contest before the game and was surprised by his skill. “He made, like, four out of five threes. So I actually had to concentrate to beat him.”

With two minutes left in the fourth quarter, and the Mavericks down double-digits, a “ROMO, ROMO” chant broke out. That’s when it happened. Romo stood up. The crowd cheered. Then he took off his warm-ups. They erupted. Then he walked toward the scorer’s table, where players sub in.

Then Cuban ran over and pulled him back to the bench.

Romo never actually signed a contract with the Mavericks so there was never any possibility he would enter the game. Was it a P.R. gimmick? Sure. (Maverick “Romo” jerseys sold out in the first quarter.) Was it a clever distraction from a team that was perhaps intentionally losing games, to better their draft picks in the off-season? Maybe. But it was also full-fledged fan service.

“I know a lot of announcers and radio guys are kind of bashing it, but I don’t see what’s wrong with it,” 23-year old Payton Betts, who was wearing a crisp Romo Cowboys jersey, said during the pregame. “I’m a diehard Romo fan so that’s why I’m here. I don’t care what happens in the game. The season is over. I’m just really here to see Romo.”

The night was a perfect storm of nostalgic appreciation for Dallas sports fans.  After a 13-3 Cowboys season under rookie quarterback Dak Prescott, a humble passing of the torch by Romo, and his recent announcement that he was walking away from football, Cowboy fans faced the blunt reality that the boyish underdog they had hung their hopes on for over a decade would never throw another pass in the NFL. They were handed a bright future without getting the chance to properly say good-bye to the past. Cuban, Carlisle and Nowitzki gave them that chance, however contrived.

It was also a night for Romo to soak in some of the gratitude that he could never fully acknowledge during his fruitless quest to win a Super Bowl. “I felt like I left something out there [in my career] that I always wanted to accomplish,” Romo said earlier that day. “I always have to live with that. This week has been special in the sense that people made me feel like they appreciated me, that they enjoyed me being their quarterback, and that meant something to them.”