Kristaps Porzingis is sleeping well these days — though Friday night might be a little tougher bed rest than most.
Before training camp opened, Porzingis took a tour of Shifman Mattress factory in Newark. The company promised to build him a special mattress — 18 inches longer than the regular king bed he had been sleeping on the past two months.
It finally arrived last weekend. Porzingis is 7-foot-3. OK, late at night, without sneakers, he’s really “just” 7-1.
“It’s great — it’s just so huge,’’ Porzingis told The Post before Friday’s 99-92 loss to the Bucks at the Garden. “I mean, I was sleeping well before that, but this is so much better. It’s so big, we had trouble getting it into the apartment.’’
The new White Plains resident was smiling as he spoke. Why shouldn’t he be? His rookie year couldn’t have been going any finer. But after Friday’s defeat dropped the Knicks to 2-4, Porzingis looked glum, even after he posted his second NBA career double-double with 14 points and 13 rebounds.
Porzingis had a blazing start but a mediocre finish, and knew it.
“I expected a better game from myself at the end,’’ Porzingis said. “I take a lot of responsibility for what happened at the end.’’
Still, the Latvian giant had two more massive putback dunks in the second quarter that drew the night’s loudest cheers, as another young New York sports stud, the Mets’ Matt Harvey, watched from courtside.
He got lax on defense down the stretch, letting the Bucks’ John Henson beat him twice inside and closing out slow on a Khris Middleton 3-pointer.
Oftentimes and again Friday, Porzingis was the most active body on the floor. He has impressing opponents, coaches, scouts and two All-Stars named Kevin Love and LaMarcus Aldridge — whom Porzingis skied above for his trademark putback dunks in consecutive games.
Nine offensive rebounds, yet zero smiles afterward.
“I’m trying to bring energy to the team and go after every offensive rebound,’’ Porzingis said. “Nobody wants to get dunked on. They’ll [have a] scouting report to box me out.’’
The grittiness and willingness to attack the glass is what has amazed about the rail-thin Porzingis, who weighs about 240 pounds. What won’t appear in the boxscore is that Porzingis drew two non-shooting fouls in the opening four minutes.
Knicks free-agent target Greg Monroe has seen him twice now, first on opening night when Porzingis notched 16 points, getting to the free-throw line a dozen times. Yes, Phil Jackson tried to convince Monroe on July 1 he could spend the next five years playing alongside a 7-3 live wire who can shoot and, yes, rebound. But the Georgetown product had his reservations and chose Milwaukee.
“I didn’t know him, not even on tape,’’ Monroe told The Post. “They talked about him, talked about everybody on the roster at that point. But I’m happy.’’
No, Monroe isn’t second-guessing his choice, but Porzingis certainly will serve as a monumental recruiting asset if he keeps this up, a lot more so than Carmelo Anthony. Porzingis is averaging 12.3 points and 8.3 rebounds in just 24 minutes a night.
“He’s pretty talented,’’ Monroe said. “He can do a lot, especially being 7-3, a really good shooter, puts it on the floor. As he grows, he’ll become much, much better. He’ll definitely be a matchup problem for a long time.’’
So instead of playing alongside him, Monroe will have to face Porzingis four times a year, perhaps wondering: “What if?’’ Monroe said the preseason talk of Porzingis needing to get stronger is bogus.
“No matter how you are, when you come in the league you have to get stronger,’’ Monroe said. “That’s just normal. It’s not like he’s a rarity that he has to get stronger. It’s a man’s league.’’
Bucks coach Jason Kidd, Mr. Fundamental, loves everything about the 20-year-old Porzingis. And that’s a great sign for the Knicks.
“He offensive rebounds, shoots, stretches the defense out to 3 and has a feel for the game, lets the game come to him,’’ Kidd said. “He doesn’t force anything. That’s cool to see a young kid like that play the level he’s playing at.’’
On media day, Carmelo Anthony fired the warning that Porzingis may not know what he’s in for.
“As far as him going into this season, I kind of feel bad for him,’’ Anthony said that day in Tarrytown. “There’s so much pressure on him … I don’t think he knows what he’s getting himself into.’’
As it happened, Anthony’s shooting woes (36.6 percent through six games) have been more troubling as he gets used to playing on his surgically repaired left knee. Anthony also withered down the stretch.
You can say Porzingis is still sleeping better than Anthony.