An MRI confirmed that All-Star forward Kristaps Porzingis tore the ACL in his left knee Tuesday night during a 103-89 home loss to the Milwaukee Bucks, the New York Knicks announced.

The injury occurred three minutes into the second quarter when Porzingis landed on Giannis Antetokounmpo's foot after converting a dunk. Porzingis' left ankle seemed to buckle on the play. He immediately grabbed his left knee after landing and was clearly in pain. Two teammates helped Porzingis off the court, and he wasn't putting much weight on his left leg.

The injury is a crushing blow for a franchise that was planning to build on a young core centered around the 22-year-old Porzingis.

Kristaps Porzingis landed awkwardly on his left leg after dunking with 8:46 left in the first half and had to be helped up and taken to the locker room. AP Photo/Mary Altaffer

As of late Tuesday night, surgery for Porzingis had not been scheduled. A timetable for his return will be established after surgery, but the expectation is that Porzingis will be sidelined for at least 10 months.

"More than a basketball player, he's my brother,'' Knicks center Enes Kanter said before the diagnosis was revealed. "I don't want to see anyone going down like that, hurting his knee. He's about to be an All-Star. I'm just going to pray for him tonight. He is the most important part of our family.''

Knicks teammate Willy Hernangomez, Porzingis' friend since their days in Spain's professional league, took to Twitter to show support.

This is so hard....you are my best friend. We have been together almost every day for five years. But, I know you will be back stronger and better than ever!!! I love you bro! pic.twitter.com/MEFurC1Asu — Willy Hernangómez (@willyhg94) February 7, 2018

Porzingis is averaging a team-leading 22.7 points and an NBA-high 2.4 blocks per game.

He previously missed two games because of a left knee issue and two games because of an ankle injury. In all, he has missed seven games this season and 33 over the course of his first 2½ seasons in the NBA.

His injury will have a ripple effect for New York. Before Porzingis went down, the Knicks remained hopeful of making a playoff run and planned to operate at the deadline with intentions of remaining competitive. With Porzingis hurt, the Knicks (23-32) probably will recalibrate those plans and look to play young players such as Frank Ntilikina and Trey Burke more often in the final 27 games.

Injuries to other Knicks also might play a role in those plans.

Tim Hardaway Jr. left Tuesday's game after being kneed in the left shin, the same area where he suffered a stress reaction earlier in the season. Hardaway's status for Thursday's game at the Toronto Raptors is unclear, though X-rays came back negative. Kanter revealed after the game that he will need oral surgery to repair a gash in his mouth that was being held together by stitches.

The Knicks were comfortable with the idea of offering Porzingis a rookie extension this summer. It is unclear how the injury impacts those plans. This summer will be the first time that Porzingis will be eligible for an extension that is worth at least 25 percent of the salary cap.