Easily one of the biggest decisions for the Knicks this summer is what they do with Immanuel Quickley, who they drafted three years ago and is coming off a big developmental season. He’s now extension eligible and is due a healthy new contract for his performance and potential, but New York could use his value in a star trade or let him hit restricted free agency in a year.

It’s hard not to want Quickley to stick around. The Knicks drafted him 25th overall at the urgent behest of William Wesley, and the deep draft gamble went from roster spot-filler to key prospect in a matter of weeks.

Not originally in the rotation, Quickley proved himself early in his rookie year, working his way into nearly 20 minutes a night off the bench with his sparkplug scoring. He averaged 11.4 points a night on 38.9 percent shooting from three, drawing Lou Williams parallels with his skinny frame but scary output.

Year Two came with big expectations for Quickley, but his deep ball suffered regression, and he had a rocky campaign along with the team at large. There was good news, as he looked improved defensively and finishing inside, two areas he was somewhat lacking in his rookie season.

After a rough start to this season, Quickley found additional freedom with the benching of fellow guard creator Derrick Rose. With more playmaking duties on him and the team finding itself on both ends, his leap year kicked off.

All the little interesting tenants of Quickley’s game finally blended into a complete, winning package of a basketball player.

His defensive potential turned into defensive prowess seemingly overnight, and he became such a prolific pest all over the court that Tom Thibodeau closed many a game with him. His offense finally balanced out, with his shot falling and his in-between and finishing games fleshed out more than ever.

Quickley put up 14.9 points on 52.1 percent shooting from two, both career highs, and 37% from three. He became a force on the boards, averaging 4.2 rebounds, and improved his passing with 3.4 assists per night.

For the back 70 percent of the season, Quickley looked like the team’s third or fourth best player. Thibodeau could throw him in any lineup, leading the bench unit or pairing him with Jalen Brunson, and success would follow.

In terms of on/off numbers per 100 possessions, Quickley was among the team leaders, with the Knicks outsourcing opponents by 6.2 points with him playing and going negative without him. All this coalesced into a second-place finish for Sixth Man of the Year, which many thought he deserved to win outright.

Unfortunately, his postseason was less fruitful. As the Knicks bulldozed their way through Cleveland, Quickley looked a bit frazzled, shooting sub-40 percent from the field and sub-30 percent from three.

He had a big closeout Game 5 with 19 points in 30 minutes of action, but was otherwise not as dependable as he was in the regular season. He struggled mightily against the Heat as well until he got injured and had to miss the final three games of the series, an ignored factor of the Knicks' demise.

The playoff yips might scare folks, but he was still himself defensively and managed to get in the paint plenty. For those reasons, he can’t be discounted as a typical gunner who struggles when every inch of the game matters.

With that in mind, along with his meteoric rise in three seasons off the bench, the Knicks ought to extend him. They have few paths to contention outside of trading for a super-duper star, but their best one is developing the talent they already have to make up for that gap in production.

Quickley is one of their best case studies of the Leon Rose era. He was legitimately crucial to this year’s success, an absolute team player, and will be worth every dollar of the $20 million a year likely headed his way.

The alternatives are trading him for a Joel Embiid-type player, or waiting to sort this out in restricted free agency. The former is unlikely to happen and the latter hurts their flexibility and perceived commitment to their developing star.

Trading him in a mid-tier upgrade for somebody like OG Anunoby would be a mistake, given at 23 years old, he has the potential to be as good. Quickley’s earned his spot as a tenant of this team’s young core, and they’ll be happy they re-signed him for years to come