PHILADELPHIA — Once again, the shorthanded Nets dug too deep a hole to escape. And once again, Ben Simmons did entirely too much of the digging.

Playing their seventh straight game without Kevin Durant, the Nets lost a 137-133 heartbreaker before a venomous sellout crowd 19,772 at Wells Fargo Center.

“The result is the result and that’s what I told the group after the game. This group that’s in the locker room right now, when we line it up against the opponent expect to win. There’s no if, ands or buts,” said coach Jacque Vaughn, whose Nets were tied at 120-all but coughed up a decisive 8-2 run.

The Nets (29-18) fell to 2-5 since Durant sprained his right MCL, and they desperately need to get Simmons in gear, for the short and long haul. The crowd booed his every touch, and probably would have booed his every breath if they could. Such is the city’s hatred of Simmons after he requested a trade last season in the wake of a deteriorating relationship with Joel Embiid, and got dealt to the Nets in exchange for James Harden.

But the Nets didn’t lose because of Embiid. He was largely outplayed by Nic Claxton, who had a career-high 25 points on 11-for-12 shooting, while adding 11 rebounds. Embiid and Claxton even went face-to-face and got double technicals late in the first quarter.

The Nets also didn’t lose because of their former star, Harden. They lost because of a sloppy second quarter from which they never recovered. They were outscored 34-24 in the second and never took the lead again.

And they also lost because Simmons, despite finishing with 12 points, five boards and five assists, was terrible for the first two quarters and largely was planted on the bench for the fourth.

Despite holding Embiid to an inefficient 26 points on 6-for-18 shooting, the Nets trailed by 17 in the third quarter and were still down 116-102 in the fourth before pulling even with an 18-4 blitz. They tied it at 120-120 on a Seth Curry 3-pointer with 4:06 left, but they ran out of gas and conceded an 8-2 mini-spurt by the Sixers that proved a bridge too far.

“It is what it is. That’s coach’s decision. I can’t really control that. Obviously for myself, I want to be out there,” said Simmons, who was largely benched late in wins at Utah and Golden State as well. Why? “I really haven’t had no message from [Vaughn]. But I think it’s more just wherever team needs to win. If we’re winning I have no problem with it, but if we’re losing then I’ve got an issue with it.”

Kyrie Irving (30 points, 10 assists) made a finger roll to make it 133-131 with 45.2 seconds left, but Harden hit one of his own with 23.9 seconds to play.

Yuta Watanabe then cut the lead in half, but De’Anthony Melton iced it from the line.

The Nets’ rally fell short. Curry — who arrived in the deal with Simmons last February — had 10 of his team-high 32 in the fourth quarter, while Simmons logged just 3:03 in the final period.

“It’s the message that talked about before the game, [it’s] we’re gonna get every guy — and that’s including Ben — to value every possession, to play hard every possession,” Vaughn said. “You become what you think about. So if you’re thinking about being aggressive, you’ll be aggressive. If you think about being a good teammate, you’ll be a good teammate. If you think about competing and playing hard, you do those things. You become what you think about.

“That’s the goal, that’s where we’re going to get him to where each possession he has to be dealt with on both ends of the floor, where you feel him on both ends of the floor, and he imposes his will. … That’s the challenge and we’re going to continue to expect it from him. Like I told him, we expect when we step out on the floor, no excuses at all.”

After Simmons had a scoreless first half, he scored 10 points in the third. He finished the night a wretched minus-16.

“Just don’t lose confidence in him and look him eye-to-eye and just hold him accountable,” Irving said. “We don’t want to duck anything when it comes to us building camaraderie. When I say duck, it just means sometimes confrontation’s good.”

Next up are the Pistons on Thursday at Barclays Center.

“We’ve got to win [Thursday],” Simmons said. “That’s it. We’ve got to win.”