Hancel Rincon’s MLB debut came with a little more drama than the Cardinals rookie probably expected, and it had nothing to do with his pitching.

It was his cap.

Rincon was told by home-plate umpire Doug Eddings to straighten his tilted hat during Friday’s game against the Colorado Rockies. A day later, players on both teams were wearing their caps tilted in an apparent show of support for the rookie.

The unusual sequence began in the sixth inning of Friday’s game, when Rincon entered for his first major league appearance. The 24-year-old pitcher from the Dominican Republic had his cap tilted so that the brim pointed toward the left when Eddings instructed him to straighten it.

Rincon complied, but the request quickly became a bigger issue.

According to Eddings, a Rockies batter had questioned whether Rincon was allowed to wear his cap that way. Eddings later acknowledged that Rincon was not violating a written rule, instead describing the issue as an “unwritten rule” concerning uniform etiquette.

There was also some confusion over who initially raised the issue.

Rockies catcher Hunter Goodman was reported as the batter who questioned the cap. Goodman later denied saying anything about it.

“I never once mentioned the hat,” Goodman told MLB.com, saying he was focused on facing Rincon and did not care how the rookie wore his cap. Goodman also said he was frustrated by criticism he received online over a comment he said he never made.

The exchange took on a different tone when Cardinals manager Oliver Marmol confronted Eddings.

Marmol was eventually ejected from the game and criticized the umpire afterward, calling the decision to address Rincon’s cap a “power-hungry move.” He also pointed to former major league pitchers including Dontrelle Willis, CC Sabathia and Pedro Strop, who have worn their caps noticeably tilted.

Marmol said he took particular issue with the timing. Rincon was making his major league debut, and the Cardinals were leading 4-1 when the cap conversation happened.

After adjusting his hat, Rincon retired Goodman before allowing a triple to TJ Rumfield, an inside-the-park home run to Cole Carrigg and a single. Marmol then came onto the field to argue with Eddings, resulting in the manager’s ejection.

Despite the rough inning, St. Louis mounted a late comeback. Iván Herrera hit a three-run home run in the ninth inning to give the Cardinals a 7-6 victory over Colorado.

By Saturday, the cap had become something much bigger than a uniform issue.

Photos and video from the game showed Cardinals players wearing their caps tilted during warmups, with many continuing the look in the dugout. Some players also tilted their batting helmets after reaching base. Several Rockies players appeared to join them, turning the unusual moment from Friday into a visible show of solidarity.

The players have not all publicly explained their reasons for wearing their caps that way, so it is difficult to say exactly what each player intended. But the timing made the gesture hard to miss.

For Rincon, the support from his teammates was clear.

“I felt big support from my teammates,” he said through an interpreter.

Eddings also spoke with Rincon before Saturday’s game and apologized for the previous night’s incident, according to reports. Rincon said he accepted the apology. Eddings also spoke with Marmol, although the manager said there was nothing particularly meaningful about their conversation.

Cardinals pitcher Matthew Liberatore said the team’s response reflected something bigger about the clubhouse.

“We’ve had a few rough stretches here, but the one superpower that we’ve had through this whole season is our ability to unify,” Liberatore said.

The Cardinals went on to lose Saturday’s game 10-5 to the Rockies, but the tilted caps had already become the defining image of the weekend series.

For Rincon, a moment that could have simply been an awkward footnote to his first major league appearance instead became a reminder that his teammates were willing to stand with him.

All over a cap.