Throughout the summer, the Knicks spoke of their impending rebuilding around a core of young players — draft-pick point guard Frank Ntilikina, athletic free agent Tim Hardaway Jr., All-Rookie Team center Willy Hernangomez and New York’s favorite unicorn, Kristaps Porzingis.

Finally, the rebuilt squad was ready for its home unveiling Saturday as the Knicks, after a season-opening thumping in Oklahoma City, faced the Pistons. But the blueprint was altered.

Ntilikina was hurt — again — and Hernangomez is down on the depth chart, somewhere south of Kyle O’Quinn. Hey, Hardaway played. Allegedly. And Porzingis was his team-high-scoring self.

But two of the centerpieces of the latest process were spectators. Ntilikina and the 6-foot-11 Hernangomez (who admitted, “I was mad” about only getting a garbage-time cameo Thursday) did not play as the Knicks blew a 21-point lead and lost 111-107. And he wasn’t too thrilled after this game either.

“The same. I’m still mad,” Hernangomez said. “I cannot help the team win if I’m sitting on the bench. Two games in a row. It’s tough. I have to wait my moment. I cannot say nothing more.”

Ntilikina, who missed summer league with a knee injury, sat after rolling his ankle at practice Friday.

Ntilikina’s street clothes did not click with a monstrous billboard on the side of a building near the Garden showing his likeness and proclaiming, “NYC Wants it All.” Actually, NYC just wants the playoffs — or at least a realistic shot at the postseason with the latest drought at four years.

“I saw it,” Ntilikina said. “It’s crazy. I love it. It’s beautiful.”

One thing he’d love more is a clean X-ray.

“I’m a little upset about it. Now it’s just hurting a little bit,” said Ntilikina, admitting the latest stall to his career is frustrating. “It is a little bit. I want to be out there and play and get experience and just play basketball.”

But at least Ntilikina knew why he sat. Hernangomez’s situation is more curious. Enes Kanter, with six seasons of creditable offense and questionable defense behind him, started with O’Quinn coming off the bench. At Oklahoma City on Thursday, that was one of the prime storylines — after the 17 involving Carmelo Anthony. Hernangomez, 23, played the final 3:46 of a blowout.

“They’ve always said, ‘Play the guys that have earned it in practice.’ That was all before we traded for Enes Kanter, so that added another center,” said coach Jeff Hornacek, who spoke to Hernangomez early Thursday, telling him he needed to concentrate on defense.

“I think I’m not that bad on defense, so it’s trying to make an impact on the team, try to do important things that the team really needs,” Hernangomez said. “I feel like I can really score, but we have other good players on offense, like KP, like Tim, so I have to make my impact on defense because on offense we have very many great players.”

Let’s not get carried away.

“That’s why I have to keep pushing my work on defense,” Hernangomez said. “It’s not because I’m a bad defender it’s just because the team needs [an] impact.”

But Hernangomez, with a competitive nature, admitted he was ticked Thursday.

“I was mad,” Hernangomez said. “But I have to keep working and wait for my moment. I know I’m ready. I showed last year I can play here. I really love playing here in New York. … I want to win. This city and the fans, they love the effort, they love to win, so I try to show I can really play and help the team win.”

Knicks fans have had little besides effort to root for in recent years and inevitably scour college scouting reports to see who the lottery pick might be this time. So they anticipated a rebuild around four young guys — or two, as was the case Saturday.

“It’s a competition. Guys earn their minutes,” Hornacek said. “Willy’s done well. … His opportunities will come.”

If they don’t, on a team most predict will fall short of 30 victories, they may never come.