Sophomore jinx refers to a player who was a standout rookie but fell behind in his second season due to multiple reasons.

Perhaps the newness of the player’s game no longer is fresh and opposing clubs have adjusted to his style.

Immanuel Quickley was selected Second Team All-Rookie last season — an accomplishment that escaped RJ Barrett.

The Knicks combo guard began the 2021-22 season following that path for second-year players. Until Milwaukee happened.

The ever-popular Quickley was excellent in the second half of Friday’s road game to help propel the Knicks to their potent, come-from-21-points-behind victory over the Bucks.

Quickley was a plus-18 and had three steals. He also made 4 out of 9 shots, 1 of 3 3-pointers, and scored just nine points. “He gave us really good minutes,” Knicks coach Tom Thibodeau said.

It was the first true “Quickley Sighting” of a subpar start to his second season. “It was our chemistry,” Quickley said of the comeback.

Quickley, ever the bold Kentucky guy, sounded hardly nervous.

“I don’t think it’s really a slump,” said Quickley, who is shooting 30.4 percent from the field, 22.6 percent from 3-point land. “I haven’t made some shots but it’s a long season. It’s not a 10-game season. It’s an 82-game season. I just continue to stay in the gym, work hard, trust God and I’ll keep my confidence high.”

Quickley has just one double-figure outing — in that massive road rout of Orlando on Oct. 22 when he scored 16 points.

His numbers are down across the board; he’s averaging just 5.7 points, down from 11.4 last season. His minutes per game have also decreased from 19 to 14.

Quickley stated that his coaches have encouraged him not to change his mindset. His 3-point shooting abilities began to decline during the Las Vegas summer league. Strictly used as the starting point guard running the show, Quickley appeared off kilter with his 3-point shooting and wound up finishing just 12 of 50 from beyond  the arc in five games in August.

“It’s an 82-game season,” Quickley said. “I’m not too worried about it. That just means I’ll play great the rest of the season if I’m not playing great right now. They just told me to be myself, which means have confidence, play hard and keep your energy on the floor. That’s what I continue to do.”

One theory is the officiating rules have changed where players trying to draw fouls with non-basketball moves aren’t getting the calls. As a rookie, Quickley was the master of such maneuvers.

“Yeah, it’s a lot more physical,” Quickley said. “When you’re going to the rack, we’re not getting as many calls — as you can see against Indiana. This game (vs. Milwaukee) we didn’t get to the line as much as we did last year. So we adjust to how it’s called. We also shoot a lot more 3-D now. We just make an adjustment to how it’s called.”

Knicks executive William Wesley and former Kentucky assistant Kenny Payne implored GM Scott Perry and president Leon Rose to select Quickley 25^ThHe was selected in 2020 because of his potential as a great 3-point shooter. This has to change.

Starting PG Kemba Walker will sit out Sunday’s first leg of a back-to-back set — a routine he had last season in Boston. Walker has scored just nine points in the past two games.