The only question is whether Jeff Hornacek will replace Derek Fisher in the history books for worst single-season record for a Knicks coach. Probably not, but after an 0-5 preseason, it’s not out of the realm of possibility the rebuilding, post-Carmelo Anthony club could challenge 17-65.

The new regime of Steve Mills and Scott Perry have never once mentioned the playoffs as an aspiration, but instead talked up developing the young core and owning their first-round picks.

In preseason, Hornacek invoked a comparison to Sixers coach Brett Brown, master of the tank. A professional blackjack player would tell you if ever there’s a season to drop to the bottom, this is the one, with lottery reform set for 2019.

“Of course I want to focus on the playoffs,’’ Knicks center Enes Kanter told The Post. “But we have a lot of young players trying to get better and [get] used to playing with each other long-term. Look at this team in five years, it’s going to be unstoppable. Every player in this team has something special.”

The Knicks grew their 25-and-under battalion from five players to seven with the Anthony blockbuster. Kanter and sharpshooter Doug McDermott, likely their sixth man, are both 25.

The former OKC duo joined fellow 25-year-old Tim Hardaway Jr., their starting shooting guard; French rookie first-rounder, point guard Frank Ntilikina (19); starting power forward Kristaps Porzingis (22); center Willy Hernangomez, (23), who likely backs up Kanter; and backup guard Ron Baker (24). Rookie second-round pick Damyean Dotson, 23, is knocking on the door for admittance to the Baby Knicks club.

For now, it probably will look dirty. The five projected starters have been put in grander positions than they’re accustomed.

Starting point guard Ramon Sessions has been a career backup, Hardaway Jr. has started 62 games in four seasons and Kanter was Steve Adams’ caddie in Oklahoma City. Porzingis is now tasked as leading man and 6-foot-5 Courtney Lee shifts to a new job at small forward.

Then there’s the front office. Mills added Perry to run the daily operations as general manager. Perry, 53, never has possessed this much clout in his NBA career and arrives off a failed five-year rebuild in Orlando.

But Perry has a big reputation as a “bridge builder’’ and spent seven illustrious years as a Pistons executive during which they advanced to two NBA Finals.

“Scott was a big part of a decade of success in Detroit,” former Pistons GM Joe Dumars, president of the ISE Basketball agency, told The Post in an email. “He understands that you have to reach the person before you reach the player. Creating a great culture is imperative to building a contender.”

With his Pistons background, Perry also arrived spewing a defense-first mentality. That didn’t manifest itself in preseason when the Knicks finished with the league’s worst defensive rating (points per 100 possessions).

“We got to pound the rock every single day into the team on how important defense is,’’ Perry said before a preseason game in Washington. “Defense is one of the pillars to building a high-level basketball team in this league.”

Losing often breeds locker-room discontent. Veteran leaders Lance Thomas and Joakim Noah have their work cut out, as does emerging voice Porzingis, who has demonstrated moodiness. The Knicks didn’t go away for training camp but bonded at a Westchester hotel.

“It’s easy [keeping morale up] now, it gets tougher all year long,’’ Hornacek said. “That’s what we want. It’s easy now. If things get tougher, will be still hang together like that?’’

Starting five

Will the end of the failed Carmelo Anthony Era breathe new life into organization?

Incapable of winning with Anthony no matter the cast he assembled, Phil Jackson wanted him gone. So did Mills when he took over for the Zen Master as team president. Management and the coaching staff seek a defense-first franchise with an array of ball-sharers and gritty defenders who take charges and dive on the floor for loose balls. Those aren’t Anthony’s traits. In fact, last season Anthony was second in the NBA in contested shot attempts. This is a fresh start after four non-playoff years with Anthony as leader and A-list scorer. Odds are the first Melo-free season will pass without a playoff berth, though that may not be such a bad fate as they treasure their 2018 first-round pick.

How long is Hornacek going to last?

Unless there’s a Porzingis-led mutiny, it’s hard to imagine Hornacek doesn’t finish out the season — regardless of won-loss record. Knicks management seem just as content to dabble in the lottery for this one season, considering the franchise-type potential forwards available in draft, including Michael Porter Jr., Luka Doncic and Marvin Bagley III. But if the defense doesn’t become more reliable and the Knicks locker room again turns into an army of grumblers, Hornacek likely will not finish out the final season of his three-year pact in 2018-19. While Mills supported Jackson’s hire, those in the know believe if Mills ran the show, he would have tabbed overseas legend David Blatt, his former Princeton running mate and groomsman at Mills’ wedding. While Blatt failed to relate to the U.S.-born star player as Cavaliers coach, the Knicks’ makeup could be well-suited with its heavy European flavor. Mills also lobbied for Mark Jackson over Derek Fisher. The knock on Hornacek is he isn’t tough enough and didn’t stand up to Jackson when the Zen Master forced his hand on the triangle before last season’s All-Star break. Hornacek was plenty rough on Porzingis, who didn’t take it kindly.

What will a Melo-free offense mean for Porzingis?

By playing mostly power forward, the 7-foot-3 Porzingis should be able to shoot over his defender. But the scouting report is if you get physical enough on Porzingis, it throws him off rhythm, especially on post-ups. Even Porzingis admits to the challenge of getting the same amount of open looks as he did his first two years now that Anthony is gone. Jackson didn’t think him ready for the No. 1 scoring option at age 22. He may have to grow into the role, finally getting cracks at the late big shot. Porzingis’ career 34.6 3-point shooting percentage could stand to rise.

Will Tim Hardaway Jr. earn his $71 million?

In his second stint with the Knicks, Hardaway Jr. is the outright starter at shooting guard and will battle Porzingis for No. 1 option late in games. Hardaway prospered in preseason averaging 17.8 points on 50.7 percent shooting and 43.2 percent from 3. By all accounts, Hardaway is in better shape and stronger than when he was with the Knicks from 2013-2015 and puts out more on D. The only offensive concern is he could get too greedy and rush his shots.

Will the point-guard dilemma be too much to overcome?

It’s safe to report now that Ntilikina is more French project than a Dennis Smith Jr. impact rookie. After missing four of the five preseason games because of a bruised right knee, he’ll come off the bench at the outset, playing behind Sessions. Baker also is in the mix to play some point guard. Sessions looked good pushing the pace but isn’t much of a finisher and the Knicks would rather have Ntilikina on the court 20 minutes a night, especially as a defender. But can he stay healthy? Of 10 eligible games as a Knick, including summer league, he’s missed nine. Jarrett Jack will be around the first 12 games with an extra roster spot opened by Joakim Noah’s drug suspension but looks washed up. The rest of the league is stacked at point guard with proven monsters. Not the Knicks.

Buzzer beaters

Newcomer to watch: He’s only 19 years old, but the plight of Frank Ntilikina will be fascinating. The durability concern is related to his toothpick-thin build and perhaps a lingering knee issue. Hornacek made an odd comment in preseason that Ntilikina’s summer-league health woes were related more to an alignment issue. But there’s a lot to like if he’s healthy. Though not a scorer, he’s got a high basketball IQ, is a willing, smooth-as-silk playmaker and a long-armed defender who can shoot adequately from 3.

Most important organizational decision: Porzingis’ happiness is a vital component to this rebuilding season and in evaluating his future. His attitude has been excellent in preseason, refusing to get into specifics on why he blew off his April exit meeting that ultimately led to Jackson’s dismissal. But at least he has sounded positive about management’s patient approach. If the Knicks have made only marginal progress by the time he’s a restricted free agent in 2019, he’ll want out — especially since his agent/brother, Janis, is already on record stating he’s displeased with how the organization developed him last season. If Porzingis enters his final contract year next offseason and isn’t remotely interested when eligible for a contract extension, the front office needs to make sure it has its ears open for potential offers.

Good days to come: Sharpshooting forward Doug McDermott is a career 39.4 percent 3-point shooter and he may have found a good fit in Hornacek’s high-tempo offense as a sixth-man sniper at age 25. He’s in the last year of his rookie contract, so the one-time college player of the year can’t possibly be more motivated to finally reach his potential.

Bad days ahead: Center Joakim Noah understood during preseason he wouldn’t get much game action since he was out the first 12 games finishing up his drug suspension. Despite impressing Hornacek in camp, Noah’s playing time likely will be limited with the Knicks going young with Enes Kanter, Willy Hernangomez and Kyle O’Quinn. Can a buyout of his monstrous contract be in the offing?

Don’t be surprised if … Kyle O’Quinn is dealt to a team looking for frontcourt depth as the club tries to alleviate a center glut. He’s been shopped at the last two trade deadlines and his energy, activeness and modest contract are assets.

Story that won’t go away: Porzingis still has to overcome durability issues if he’s to develop into an All-Star this season and superstar in a few years. He missed 10 games in his rookie season and 16 last year, plus was limited in preseason. This bears watching in Year 3.

Five games to watch

Oct. 19: at Oklahoma City

The NBA was prescient in scheduling this doozy in August. The Carmelo Anthony trade was agreed upon Sept. 23. Anthony will take relish in piling it on his former team that didn’t want him. But popular ex-Thunder center Enes Kanter may make some waves, too.

Nov. 13: vs. Cleveland

Derrick Rose is back at the Garden … with LeBron James as his partner.

Jan. 7: at Dallas

Point guard Dennis Smith Jr. was there for the taking at No. 8 but Phil Jackson went French. Smith is ready to punish the teams who passed on him and GMs think he may be Rookie of the Year.

Dec. 16: vs. Oklahoma City

Anthony is in before Christmas and he’ll hear a lot more holiday jeers than cheers. Knicks face big decision whether to put together a video montage of his highlights. They’d be mostly regular-

season ones.

Dec. 21: vs. Boston

Kyrie Irving, Gordon Hayward and ex-Dukie Jayson Tatum enter the Garden in Celtic green for first time. Imagine, Irving wanted to make the Garden his permanent home.

Three bold predictions

1. With a scoring average topping 20 points, Kristaps Porzingis is selected as an All-Star reserve.

2. Center Enes Kanter is traded at February’s deadline for an expiring contract and first-round selection.

3. Two-way rookie shooting guard Damyean Dotson gets voted into the Rookie-Sophomore Game over Frank Ntilikina.

The Post’s forecast

24-58

The unclear point-guard situation will keep them from competing this season and Porzingis and Hardaway Jr. have new big-time roles and will need a season to adjust. They’ll go younger and younger as record spirals downward. The lottery drawing will be fun to watch in May.