Sixers players party with the owners, which fosters insubordination toward Brett Brown | Marcus Hayes

When you hang with the big bosses, you don’t fear your supervisor.

The Sixers’ most visible limited partner, Michael Rubin, on Sunday fired off an Instagram post from Super Bowl LIV like thousands of others. On the surface, it looked like just a bunch of bros hangin’ at Hard Rock Stadium. It was much more than that. Beneath the surface, it exposed the overarching problem with this underachieving Sixers team:

The owners have undercut their coach.

The post showed Rubin, in the Super Bowl suite that his Fanatics company acquired, hoisting little movie star Kevin Hart. Co-managing partners Josh Harris and David Blitzer look on, smiling. So do the team’s three best players: Joel Embiid, Ben Simmons, and Tobias Harris.

The next night, the Sixers got blown out by the Miami Heat. They were disengaged, uninterested, dysfunctional. It was their third loss in a row, and it might have brought coach Brett Brown to the brink of termination.

The players didn’t play like they were hung over, or even exhausted; they actually left the Super Bowl long before midnight. The players played like they’d tuned Brown out. One source familiar with the organization texted a prolonged laugh when addressing the issue.

One team source was asked if Brown was guaranteed a job if the Sixers get manhandled in Milwaukee on Thursday. That source offered Brown no guarantees.

Why? Because every team source we spoke to, on and off the record, recognizes that the club has festering problems that go far beyond Brown’s acknowledged lack of offensive identity. These problems center on whether the players will play hard in the last 31 games, and if they will obey their coach’s commands.

Why should they? Carson Wentz and Fletcher Cox won’t be throwing back with Jeffrey Lurie at the NBA All-Star Game. It’s simple psychology: If the players party with the owners then, when the players are unhappy with the coach, the owners will have their backs.

According to three sources in the professional sports industry, Embiid and Rubin had become very close, sometimes jetting around the country for junkets and retreats, occasionally with Patriots owner Robert Kraft and Meek Mill, with whom Kraft and Rubin are pursuing criminal justice reform.

Several Sixers cast Rubin as a counselor and confidant for Embiid, who is an emotional, passionate, 25-year-old who will have earned more than $70 million by May — a rich, entitled, young man whose psyche can be as fragile as his body has proven to be.

In today’s world of professional sports, it’s naïve to think that owners should not have relationships with their chief investments — in this case, three players who will make a combined half-billion dollars under their current deals. It also should be recognized that ownership might occasionally need to insert itself, when dealing with the biggest names and the biggest egos.

But the Sixers do this far too much.

It breeds insubordination. Why should Embiid listen to his coach, lose weight, and get his rest? Why should Simmons take three-pointers, as Brown ordered him to do Dec. 7? Simmons has taken zero threes in the 28 games since, a clear refusal to follow orders. Why bother to embarrass himself with his funky shooting form when he knows he’s going to be sitting next to the principal owners, watching Shakira and J-Lo shake their middle-aged assets?

This is the root of the problem. The players are unafraid to lie down on any given night.

Granted, Brown hasn’t been his own best ally. He believes more in the carrot than the stick, particularly in the case of this sensitive NBA millennial/Gen Z (who are way less sensitive than boomers, but still). He feels more like a father than a boss.

It is his tragic flaw. Spare the rod, and all that. Hence, the eye-rolling, hand-waving, dead-faced reactions from the team during its Super Monday embarrassment in South Florida.

Does Brown believe he’s still in charge?

“I’m not naive enough to not understand why you’ve asked what you’ve asked,” Brown said. “When it gets to an epidemic stage — this thing you’re talking about — I’ll admit that.”

Funny thing about epidemics.

They kill.

Brown’s shortcomings are only half of the equation. The franchise has lacked a competent, autonomous leader at any level — in the front office, among the owners (Harris speaks, Blitzer acts), or in the locker room.

This stems from the moment Harris bought the team, to the selfish mismanagement by Doug Collins in 2013-14, through Sam Hinkie’s aimless destruction and horrific draft choices, to the self-aggrandizing stumbles of Bryan Colangelo and his sugar daddy, Jerry, to Elton Brand, who now has to submit every move in triplicate for approval, like some overdue TPS report.

Brand on Wednesday declined to address ownership’s relationship with the team’s stars. Brown was considering addressing it on his way to Wisconsin but had not responded by the time this posted.

These owners didn’t become billionaires by being tone-deaf or dumb.

Rubin, who hosts celebrities at his courtside seat across the court from Harris (who sits next to the team), was noticeably less involved with the team this season than he was last season. At least, that was the case until a few weeks ago.

One team source said that Rubin now realizes that the Instagram post makes the team look foolish in this moment, but shrugged at such indiscretions, because Rubin is who he is: transparent, ebullient, and unapologetic. It’s how he turned a replica jersey company into a $3 billion business.

For the last three years, team sources have indicated that Rubin’s relationship with Embiid has been a boon when dealing with the center, whose personality and emotions are as fragile as his body has proven to be. Further, in professional sports today, it’s naïve to think that owners should not have any relationship with their chief investments, and it must be that ownership occasionally might want to insert itself.

But these relationships need to remain professional, or the players will feel bulletproof.

When the team loses to a woeful Atlanta team, then to a Boston team playing without Kemba Walker, then takes the worst road record (9-17) of any team over .500 into Miami, and ownership entertains them at the biggest sports party of the year, it sends this message:

You players? You’re not the problem.

So you can fire Brown. Trade Embiid, or Simmons, or whomever.

No matter who the coach is — whether Brown stays or goes — if the Sixers expect to win, that message from ownership has to change.