Reggie Bullock may not see the basketball court until next year.

According to a leading orthopedic surgeon who specializes in sports back injuries, the “cervical disk herniation” surgery Bullock underwent last week normally requires six months of recovery time before a player can compete with contact.

The operation is usually referred to as spinal fusion surgery and it means Bullock could be out until mid-January, forcing the Knicks’ new signee to miss the 2019 portion of the team’s schedule.

The Knicks did not release a timetable for Bullock’s return, but they had reneged on his two-year, $21 million deal after his physical was red-flagged earlier this month. The second year was a team option.

Under a subsequent arrangement, Bullock will make $4 million next season, according to a source, with the second year a team option. That essentially will cut his wages by more than half — appropriate for a player who will miss all of training camp and preseason and likely the regular season’s first three months.

A six-month absence from competition is commonplace, according to Dr. Wellington Hsu, Northwestern University’s director of research/orthopedic surgery.

“It’s actually neck surgery he had,’’ Hsu told The Post. “But it’s a surgery where you are able to get back to the same level as you were before.’’

Hsu gave two prime examples of that happening — former Bucks point guard T.J. Ford and superstar quarterback Peyton Manning. The spinal fusion surgery Manning underwent in 2011 led to him winning the NFL’s MVP award in 2013.

Ford played well for a few seasons after surgery, but retired prematurely in 2012 at age 28. Bullock is also 28. Ford, the former Texas star, had spinal fusion surgery his rookie season in 2004 and was forced to sit out the entire following season.

“It’s not as common in basketball players as football players because of the contact,’’ Hsu said. “Most of the time in basketball it’s arthritis and wear and tear on the disk. The disk bulges and more severely, herniates, putting pressure on the nerve [in the neck]. Defensive backs are very prone, needing to use their head and neck to tackle players 100 pounds heavier than they are.’’

The symptoms Bullock experienced were likely neck and arm pain, according to Hsu, who has not treated Bullock. As dangerous as neck injuries can be, it’s “very rare’’ Bullock would be at risk for potential paralysis if he reinjures his neck upon his return, Hsu said.

The surgery calls for the entire disk to be removed and replaced with a bone graft and a cage. The six-month period without contact allows the bone grafting to take hold, according to Hsu.

Bullock missed 19 games last season (splitting time with the Pistons and Lakers) with neck stiffness and plantar fasciitis, though his 63 games played were his career high. The injury-prone shooting guard has averaged just 45 games per season in his six years after being a first-round pick of the Clippers in 2013.

Disk injuries are a tricky issue. Late last season, Knicks point guard Dennis Smith Jr. revealed he had been diagnosed with a couple of misplaced disks, which forced him to miss games in the season’s final month. While in Las Vegas in July, however, Smith reported no disk pain.

Even with an extended absence for Bullock, the Knicks will be deep at shooting guard. Damyean Dotson, Allonzo Trier, lottery pick RJ Barrett, newly signed Wayne Ellington and Frank Ntilikina all can play the position.