Mets manager Terry Collins has relatively few team rules, so the ones that exist are clear. For instance, any player who might not make it to the ballpark in time must notify Collins or team trainer Ray Ramirez.

But on Saturday afternoon, Mets players reported for stretching and took notice of one conspicuous absence. The time for notification had long passed. With that began another round of drama with Matt Harvey, one that again has chipped into his credibility among his own teammates.

According to multiple sources, at about 4 p.m. Saturday, after team personnel had tried unsuccessfully to reach him, Harvey sent notice to pitching coach Dan Warthen that he had a migraine headache after a morning round of golf. It was his only communication with the Mets that day, according to people briefed on the matter, leading to a course of action that one team official said was designed be “more than a slap on the wrist.”

“He wants to be Derek Jeter,” said one teammate, summing up the internal frustration with Harvey. “To do that, you’ve got to show up.”

Team officials grew concerned enough to send security personnel to check on Harvey’s welfare at his residence on Saturday night, sources said. The club already had resolved to send a message, suspending Harvey for three games without pay, an action that was greeted with approval in the clubhouse.

“Something had to happen,” another teammate said. “There had to be a sense of accountability.”

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Harvey’s suspension meant certain defeat for the Mets, who scrambled to find a replacement starter for Sunday’s series finale against the Marlins. The Mets were 14-15 and in need of a turnaround from what has been a bruising season of injuries. Adam Wilk was summoned from the minor leagues and took the mound on little sleep after flying across the country. The result was a 7-0 loss to the Marlins.

There appeared to be little doubt about the proper course of action for the Mets, who have long drawn criticism for showing leniency to star players.

In the clubhouse, among those fed up by Harvey’s behavior, there was relief that a message had been sent. The move was regarded favorably despite Harvey’s reported plans to file a grievance for a suspension that will cost him about $80,000.

Harvey is expected to return on Tuesday and is expected to address the matter. Agent Scott Boras did not return a text for comment.

“People make mistakes,” said Jay Bruce, reflecting a desire within the clubhouse to move past the episode, partly because Harvey’s presence still is ultimately wanted.

Harvey is slated to start on Friday against the Brewers in Milwaukee, away from likely negative fan reaction at Citi Field.

Collins deflected a question about whether Harvey must regain the respect of the clubhouse. The manager sought to move past the episode, starting with Harvey addressing teammates upon his return.

“Those are questions that individual guys have to answer,” Collins said. “We’ve got to know one thing about our society: if you make a mistake, stand up, be accountable and move on. And people forget about it.”

Harvey, 28, has long been a source of contention within the Mets’ clubhouse, with some teammates bristling at his outsized “Dark Knight” persona. One teammate described a “sense of alienation” that Harvey created around himself.

That behavior ran contrary to his desire to take on a leadership role, part of the reason he lobbied to become a union representative for the team, according to several Mets.

Though multiple sources said Harvey had never been a no-show to a game, he had been late before. He was infamously tardy for a workout in advance of the 2015 postseason, which initially was explained as an issue with traffic. In 2016, Harvey was late to one of the team’s exhibition games in Las Vegas, home of its Triple-A affiliate.

In each case, sources said Harvey was fined $500 and then given the chance to have the fine wiped away with a strong performance. Both times, he won back the fine.

Even after that checkered history, several Mets said Harvey carried himself differently this season, making more of an effort to fit in. However, Saturday brought forth the first signs of yet another turn.

A day before, he wore a tank top that read “Saturdays Are For The Hamptons,” perhaps a humorous reference to his reputation for partying. On Saturday, as the Mets stretched with no sign of Harvey, a few took note of the timing. The previous night had been Cinco de Mayo.

Said one Met: “You could see all of this coming.”

Harvey, it appeared, had not. Sources said that when he arrived at Citi Field on Sunday, he signaled little awareness about standing in the eye of yet another firestorm.