This one hurts differently for the 76ers.

That’s not a knock against Tobias Harris, Matisse Thybulle, and Isaiah Joe, who are in the NBA’s COVID-19 health and safety protocols. But the weight of the Sixers rests on Joel Embiid’s shoulders.

The four-time All-Star has to play at an elite level, remain healthy, and stay in shape for the Sixers to contend for their first NBA title since 1983. Embiid, who is vaccinated, tested positive for COVID-19 on Monday and joined his three teammates and a staff member in protocols.

A vaccinated player can typically return after a 10-day quarantine or following two negative tests 24 hours apart. Embiid is symptomatic. That suggests that he could be out longer than 10 days.

» READ MORE: Joel Embiid is the latest Sixers player placed in the NBA’s COVID-19 health and safety protocols

“I mean, he’s not doing great,” coach Doc Rivers said before Monday’s 103-96 loss to the New York Knicks at the Wells Fargo Center. “He’s struggling with it. It’s very similar to Tobias. That’s all I can tell you.”

Harris, who’s also fully vaccinated and symptomatic, has experienced fatigue and congestion.

So what type of shape will Embiid be in once he returns?

How will his absence impact the Sixers?

“You really want to ask that question?” Rivers said.

The coach tried not to single out what Embiid’s loss means to the team, saying, “You don’t have Joel. He’s a pretty good player,” before adding that Harris and Thybulle were pretty good, while Joe was a good shooter.

“So we just don’t have a lot of numbers, you know?” Rivers said. “So obviously, this is just a great challenge. That’s just how I want our guys to look at it. It would be a heck of a story to tell if you can pull these games out.

“And that’s what I want our mindset to be.”

The result

The Sixers dropped to 8-3 and had their six-game winning streak snapped. It also marked their second loss in as many meetings against the Knicks (7-4).

Luckily for the Sixers, Danny Green returned from his left hamstring injury that sidelined him for three games. So they went with a small starting lineup of Green, Furkan Korkmaz, Andre Drummond, Seth Curry, and Tyrese Maxey.

The Sixers battled back from a 19-point first-half deficit to pull within one point four times in the fourth quarter. The last one made it an 89-88 game with 5 minutes, 1 second remaining. But Julius Randle responded with a layup and a corner three-pointer on ensuing possessions to push the Knicks’ lead back up to six.

Then after Korkmaz drained a three, Randle responded with another one to put the Knicks up 97-91 with 2:54 left.

Then Kemba Walker added a three-point play before Randle scored on a layup to extend New York’s lead to 11 with 1:11 remaining.

“I actually thought we ran out of gas several times,” Rivers said. “It was funny. In the first half, I thought we got unbelievable open shots. You can see our heavy legs. What’s this, our fifth game in eight nights? Tomorrow will be our sixth game in nine nights shorthanded. It is what it is. I love the effort.

“I thought fatigue was an absolute factor for us.”

Randle, an All-Star power forward, scored 10 of his game-high 31 points in the fourth quarter. He also finished with 12 rebounds.

The Sixers had six double-figure scorers in Korkmaz (19 points), Maxey (16), Curry (14), Drummond (14, season-high 25 rebounds), and reserves Georges Niang (15) and Shake Milton (10 ).

Following the game, the large portion of New Yorks fans in attendance chanted, “Let’s Go Knicks! ... Let’s Go Knicks!”

Embiid had been scheduled to miss the game due to rest before testing positive. This marked the fifth straight game the Sixers were undermanned. They were without at least one key player in all of those matchups due to COVID.

Health and safety protocols

But this is definitely different when it involves the team’s franchise player with a history of being out of shape when missing extended periods of time.

The Sixers were without five players from their 15-man standard roster against the Knicks.

Ben Simmons is mentally not ready to play. Harris was placed in protocols on Nov. 1 and Joe joined him on Thursday. Joe’s diagnosis prompted the entire team to get tested for the virus before Thursday’s game against the Pistons in Detroit. At the time, everyone received a negative test.

Thybulle, whose locker is next to Joe’s, was placed in protocols one day later for contact tracing. The two also sat next to each other on the bench during Wednesday’s home game against the Chicago Bulls. But Thybulle still is out.

Then on Monday, the Sixers learned that Embiid had tested positive.

“It was shocking,” Curry said. “You never know if Jo is serious or not. But it’s just unfortunate.”

The Sixers were fortunate to sign Drummond, a two-time All-Star, this summer in free agency. He is a solid backup and an insurance policy for Embiid.

“Obviously, this is an extreme case without Joel,” Rivers said. “We didn’t anticipate this. But, we do have a bona fide starting center. And that helps us for sure.”

Huge loss

But Embiid’s presence will be missed over a sustained amount of time, especially with already undermanned team.

He is averaging 21.4 points, 9.4 rebounds, a career-high 4.0 assists and 1.4 blocks. Embiid finished with 30 points and 15 rebounds in Saturday’s road victory over the Bulls. But he’s also more of a playmaker for teammates this season.

The Sixers will entertain the defending champion Milwaukee Bucks on Tuesday. The Bucks were honored by President Joe Biden on Monday at the White House for winning the title.

“Hopefully President Biden gets the Bucks to drink at the White House today as much as he can,” Rivers joked. “But they’re going to be in fresh. Think about it: They are going to come in fresh, and we play them tomorrow.”

Then the Sixers will host the Toronto Raptors on Thursday before embarking on a six-game road trip with stops at the Indiana Pacers (Sunday), Utah Jazz (Nov. 16), Denver Nuggets (Nov. 18), Portland Trail Blazers (Nov. 20), Sacramento Kings (Nov. 22), and Golden State Warriors (Nov. 24). Assuming Embiid is out for at least 10 days, he probably wouldn’t be eligible to play until the game against the Blazers. Even that game may be considered a rush due to post-COVID reconditioning.

» READ MORE: The Sixers’ efficient offense will be tested this week as East’s elite come to Philly

Embiid needs to play frequently in order to remain in shape. And there’s really not much, if anything, he’ll be able to do basketball-wise while quarantining.

“I’m not that concerned by that,” Rivers said before Monday’s game. “I think everyone hit by this hard struggles coming back for a little. So I’m sure that will be him, too. But the conditioning part of it, you know I have a feeling he’ll be ready with conditioning.

“Bottom line, I can’t project out. We have to focus on today’s game and tomorrow’s game and then see what we have after that.”

But the Sixers have been hit hard by the league’s protocols.

The NBA sent out a memo to teams stating that the league personnel who received the Johnson & Johnson vaccine are advised to seek a Pfizer or Moderna booster shot. It said those with the Moderna or Pfizer vaccine are advised to get whatever booster is available.

“I’m pro booster,” Rivers said. “I was at Marquette. That’s a joke. I’m still pro booster. I just think if you can get it, you should get it.

“Listen, this is still out there. COVID is not over. And it’s still very much in play.”