Kristaps Porzingis #6 of the New York Knicks shoots over...

Kristaps Porzingis #6 of the New York Knicks shoots over Tristan Thompson #13 of the Cleveland Cavaliers during the second half of a game at Quicken Loans Arena on Dec. 23, 2015 in Cleveland. Credit: Getty Images / Jason Miller

The Knicks didn’t hold practice Monday, but Kristaps Porzingis said he would be in the gym putting up shots.

Porzingis has his own shooting routine for off-days but losing and his own offensive struggles are pushing the rookie more right now.

“You have that frustration you want to let it out,” Porzingis said. “You just want to get in the gym. That’s what I’m going to do.”

Porzingis should have had plenty of company the way the Knicks have been playing. They followed a four-game winning streak by dropping four straight. They’re averaging only 93 points during this skid, but Porzingis’ shooting woes are 10 games old.

He’s shooting 31.2 percent and averaging 10.3 points in those 10 games; he averaged 14.6 points and shot 46 percent from the field in the 22 games before that. Porzingis was 4-for-13 in Sunday’s loss at Boston.

“I’m getting a lot of looks and my teammates are giving me the ball,” Porzingis said. “They’re trusting my shots. They know I can make those shots. I’m just not making them. But I can feel it’s right there. It’s just in and out or a little long, little too short. It’s right there.

“It’s frustrating is what it is. But we’ve got to stay positive, stick together.”

The Knicks play the improved Pistons Tuesday, hoping to avoid their first five-game losing streak of the season.

This is not new territory for the Knicks. Since starting 8-6, this is the third time the Knicks have lost four consecutive games. Their offense continues to be the problem.

In the previous two four-game losing streaks, the Knicks scored 89.5 points and 92.5 points per game. Derek Fisher is stressing that his players are not playing with any cohesion in the triangle offense, and as a result they’re making the game more difficult.

“That’s the point that we’re trying to make to our guys,” Fisher said. “We have to find a way to play offense together and it’s going to make the game easier and allow everybody to contribute.

“It doesn’t matter what you’re running, you have to do it together. Right now we’re doing it at times, there are times where we’re getting willful; we’re trying to manufacture offense as opposed to really allowing the offense to flow.”

Fisher said that was the reason he played veteran guard Sasha Vujacic instead of struggling rookie Jerian Grant when the Knicks had trouble scoring against Boston.

“We’re still trying to find a way to have five guys that are playing together, flowing together,” Fisher said.

Too often the Knicks rely too much on Carmelo Anthony or Porzingis and get too little from their backcourt.

The Celtics’ guards outscored the Knicks’ backcourt players 51-12. Arron Afflalo, the No. 2 option some nights, has scored four points twice in the current losing streak and is shooting 31.1 percent in those four games.

Anthony said the Knicks will continue to work through their troubles and that negativity won’t creep in.

“I won’t allow that,” he said.

But Fisher wants the Knicks’ frustration to push them the way it is motivating Porzingis.

“We all are [frustrated],” Fisher said. “But I don’t think that’s going to break their spirit in terms of competing hard every night and giving themselves a chance to win games.

“It should be both emotions. We should never be OK with struggling and losing and that should actually motivate you and inspire you to do more, to be better, to work harder, to put more time in until you figure it out.”