Josh Norman believes the cohesion of the Redskins’ defense broke down as the season progressed. (Ricky Carioti/The Washington Post)

In the spirit of brotherhood, Josh Norman opened his doors. Every Thursday, the Washington Redskins cornerback provided the venue — most often his palatial 18-acre estate in Ashburn — and enough activities to entertain several grown men for hours of team bonding.

There were card games, a pool table, shuffleboard and TV screens at their disposal. On one occasion, Norman even rented out a nearby movie theater so members of the defense could watch “Thor: Ragnarok” when it was released in early November.

It was his attempt to build a foundation of trust that would aid the group’s efforts on game day. But as the season wore on, participation in Norman’s get-togethers began to wane. And that’s when cracks in the defense were exposed.

“That’s the frustrating part about it,” the Redskins star said in an interview, adding that the unit’s chemistry was “absolutely” disrupted when certain players “fell off” in attendance.

“Because if everybody’s all in on something, then you be all in. But if you’re not, then let us know. If you want to do something different, then we can do that. We can do it in however way you feel — but we will be together,” Norman stressed. “We will do things together.”

Several issues contributed to Washington’s 7-9 finish, most notably injuries and inconsistent play on both sides of the ball. But while Redskins players spent Monday afternoon carrying boxes out of the locker room and rehashing the missed opportunities of another lost season, several defensive players highlighted the unit’s lack of cohesion.

“For us to be successful, the biggest thing is we have to jell as a team,” linebacker Martrell Spaight said. “The more we jell as a team, the better we’re going to become out there on the football field. We showed signs earlier in the year when we were doing things [together], just camaraderie things, and we see it out there in our game play.”

Safety D.J. Swearinger, who routinely voiced irritation over the lack of preparation and focus shown by some of his teammates, added: “Next year, I think we’ll be better bonding together as a group, especially as the DBs.”

Like Swearinger, Norman never called out players publicly. But as he spoke candidly in a hushed voice at his locker, he made it clear he has zero tolerance for teammates who don’t put team goals ahead of their own.

“We only get six months out the year of this. Then after that, you can do whatever the heck you want to do,” Norman said. “But when you’re in the season, be in the moment. This is what you get paid for.

“We want football players,” he added. “Guys that care about nothing but playing ball. That’s it. If they don’t want to be that, they’ve got other auditions or agendas, we’ll holla at you. This ain’t the place for you.”

One player characterized it as “a few here and there” who didn’t show up on certain weeks, adding that it felt like certain guys “didn’t want to be there” because they either had plans on Thursdays or because they were tired on Wednesdays and Thursdays — the toughest practice days of the week.

Norman couldn’t definitively say when certain players stopped showing interest in his weekly hangouts, but he pinpointed their 33-19 loss to Dallas in Week 8 as a defining moment. “I just think we just weren’t together,” said Norman, who finished the season with zero interceptions and nine passes defended. “That Cowboy game, it was like a real big thing for us.”

Turnovers, torrential rain and a host of injuries helped sink the Redskins en route to their fourth loss of the season.

Heading into that NFC East division matchup, Washington ranked ninth in rushing defense, 19th in passing defense and tied for 25th in points allowed. The unit finished the year last in rushing defense (surrendering 134.1 yards on the ground), ninth in passing defense (213.8) and tied for 27th in points allowed (24.2).

In a season that began with second-year safety Su’a Cravens abruptly leaving the team and ultimately being placed on the reserve/left squad list, Washington’s defense was beset by injuries on the defensive line (Jonathan Allen, Matt Ioannidis) and at linebacker (Trent Murphy, Will Compton, Mason Foster) . And as Redskins Coach Jay Gruden juggled his lineups each week to account for those missing pieces, his defense found it difficult to maintain cohesion.

“I didn’t really think about it much because it was the first time since I’ve been in the league that we had get-togethers every week,” said Spaight, a fifth-round pick in 2015. “But the moment that we started to see the team fall off here and there, it kind of dawned on me in one moment, ‘Well, damn. I guess maybe it was kind of paying off for us to meet up each week.’ ”

But as the Redskins face an offseason full of uncertainty, Norman vowed a better, more cohesive defense is on the horizon.

The goal, he said, is getting guys who are “all in.”

“And the ones who aren’t?” Norman said, shrugging his shoulders, “It’s pretty simple.”