At this point in the season, NBA rotations are generally set for the playoffs: A couple weeks after the trade deadline, teams usually know what they have, or explicitly what they need.

Nothing, however, has been usual for the Nets this season: They’ve got a part-time superstar point guard, an MVP candidate who missed a month-and-a-half with a knee injury, a roster that was upended at the trade deadline when James Harden forced his way to Philly.

And now a star who has yet to make his debut, who very well might not play until April.

Nets head coach Nash said star forward Ben Simmons has upgraded to doing “light work on the court — a little bit of shooting, ball handling and light cutting,” but that his back soreness continues to limit him to individual drills.

“I don’t think he’s ready for even one-on-one let alone on three-on-three, five-on-five,” Nash said. “So he’s got to get to a place where he can go full speed unopposed — 1-on-0 — and then hopefully quickly can go to one-on-one, three-on-three, five-on-five.”

Back soreness is a condition Simmons has dealt with dating back to his holdout in Philadelphia earlier this season. Nash said Simmons suffered a “little setback” shortly after arriving in Brooklyn, and the team is trying to make sure Simmons’ back is resolved before rushing him into high intensity work.

“I don’t want to classify it the wrong way, but he’s had back issues at times,” Nash said. “So I don’t want to say he’s got a bad back, I don’t know if that’s fair. I think he’s had a flare-up of something, but was really healthy for the last six months until the flare-up.

“So I don’t want it to be…I’m not sure that it’s fair for me to say he has a back problem. It’s just right now he has a flared up back.”

This is an issue, of course, because there are only 15 games left on the schedule until the play-in tournament comes, a number that drastically reduces when you consider Simmons is not even close to participating fully in practice just yet.

The Nets require three high-intensity workouts without setback for a player to be cleared from injury. Simmons has yet to register one, and the Nets are running short on practice days to get him there.

Which means Simmons is going to join the team late, very late, almost too late. There’s no way around that: The Nets are going to have to scramble to fit these pieces together and test drive this product against an opponent before the playoffs.

“I think the urgency here is 15 games,” veteran guard Patty Mills said after Saturday’s practice. “We’ve just played three games with almost all of our pieces. I think there’s enough reasons for us to have the urgency to be able to string these games together.

“The holy grail is a championship and time isn’t on our side, but we have enormous opportunity here with these 15 games coming up to keep on getting better.

There’s no apples-to-apples comparison for the situation the Nets find themselves in, but Mills has had a similar experience in the past.

He was an integral piece on a championship-contending 2013 San Antonio Spurs team that added a player just ahead of their playoff push.

“I’ve had Tracy McGrady that came after the regular season into the playoffs,” Mills recalled after practice. “(He) didn’t play one regular season game, joined us for the first game of the playoffs.”

And how did that playoff run go?

“Great,” Mills said. “We even made it to the Finals that year.”

There’s one stark difference, however, between the Spurs adding T-Mac and the Nets integrating Simmons, a difference that could define just how far the Nets can go given the lack of time they have to string everything together.

McGrady was in his final NBA season, and he only played garbage time minutes for San Antonio.

Simmons projects to play a significant role in Brooklyn. Barring more theatrics from Nash, he will start alongside Kevin Durant, Kyrie Irving, Seth Curry and Andre Drummond. Simmons’ abilities as an All-NBA level defender and All-Star caliber finisher and playmaker will change what the Nets are capable of doing on both ends of the floor. As a result, he will take some getting used to, which requires time the Nets simply don’t have.

And the longer the Nets keep him out, the less time there is for them to build chemistry with all their players on the floor.

You also have to factor in Irving’s part-time availability: The Nets are a different team when their superstar guard is on the floor, but he will only be eligible to play in four more games this season unless there’s a change in New York City’s private sector vaccine mandate.

If Simmons doesn’t play in the next two weeks – by the showdown in Miami on March 26 – he will only have one regular season game alongside Irving: in Atlanta against the Hawks on April 2.

Mills, however, believes there’s just enough time for Simmons to slide in and make an impact. He sees his countryman as a perfect-fitting puzzle piece, someone who complements his teammates with “an enormous amount of knowledge, IQ, length, physicality,” and “a competitive fire that’s been building in him” for the entire season.

“I think the particular player that he is, it’s gonna work well,” Mills said. “For someone else that (may not be the case), but I think he can because he complements the pieces. I think 15 games to go will be alright.”

It’s not 15 games. It’s looking more like five, which makes the margin for error that much more slim.

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