The Knicks keep talking about making a playoff push. But when they were pushed by the Nets on Friday night, they fell down and couldn’t get up.

That’s not a good sign for the remainder of their season.

In the first game after the All-Star break, the Knicks suffered a demoralizing defeat, and they sounded more down and defeated than they have all season. It was the Nets who looked as if they were playing for something while the Knicks didn’t show much fight. They executed poorly on both ends in the second half, allowed Brook Lopez to score 33 points and dropped their seventh straight game, 109-98, at Barclays Center.

“We lost again,” Kristaps Porzingis said. “It [stinks].”

After their 11th loss in 12 games, the Knicks — who made no deals before Thursday’s trade deadline — are 10 games under .500 for the first time this season at 23-33. They’re also six games out of the last playoff spot with 26 to go. They’re in Minnesota on Saturday night and have a tough March schedule that includes 10 road games.

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“We can’t be giving away games like that,” Carmelo Anthony said. “It’s crunch time. We could have got this game, but we didn’t. Now we got one tomorrow that we have to go get.”

The Knicks led by nine points in the first half but the second half was all Nets (15-40). They also beat the Knicks on Jan. 13, not long before the 1-11 slide began.

“I thought we came out great,” Anthony said. “It felt like we were locked in, it felt like we were focused. It felt like we had the energy in that first quarter. For some reason, it disappeared after that.”

The Nets outscored the Knicks 59-46 after halftime and built a 17-point fourth-quarter lead. The Knicks never got it under 10 after that.

Bojan Bogdanovic scored 16 off the bench for the Nets and point guard Donald Sloan had 14 points and 10 rebounds. But Lopez had his way with the Knicks and twin brother Robin and was the best player on the floor. “He’s incredibly lucky when he’s playing like that,” Robin Lopez said.

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Anthony led the Knicks with 22 points, but only 11 came after the first quarter. Porzingis added 18 and Arron Afflalo had 17.

“A big part of our demise was they ramped up their pressure and we didn’t execute our offense,” said Kurt Rambis, who is 0-2 since replacing Derek Fisher as coach. “We couldn’t handle that pressure.”

The Knicks had 16 turnovers that led to 21 points overall, and their second-half defense was atrocious. The Nets shot 55.6 percent from the field and took control with a 24-5 third-quarter run that opened a 78-64 lead with 2:50 left.

“If we can’t get stops, we can’t score enough points to keep us alive in the ballgame,” Rambis said.

After the Knicks cut it to 86-83 with 9:36 left, the Nets reeled off a 16-2 run to build a 102-85 cushion with 5:38 remaining.

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For the Knicks to make a playoff run, Anthony knows he’s going to have to raise his game and hope his surgically repaired left knee holds up.

“I got to do everything,” he said. “Everything and more at this point. It’s win or go home at this point. It’s no excuses, no excuses now for myself and everybody else. We got to tighten this thing up and make a push.”