New York Knicks All-Star Kristaps Porzingis' season was effectively ended by a torn anterior cruciate ligament on Tuesday, and former team-mate Carmelo Anthony sympathised with his "little brother".

Porzingis' injury occurred early in the first quarter of the Knicks' 103-89 loss to the Milwaukee Bucks when he came down on Giannis Antetokounmpo's foot after a dunk. 

Anthony, who was traded to the Oklahoma City Thunder by the Knicks in the offseason, lamented the injury to the 22-year-old Latvian, who is averaging 22.7 points and an NBA-high 2.4 blocks per game.

"It's just sad to know," he said after the Thunder's 125-105 victory over reigning NBA champions the Golden State Warriors on Tuesday.

"That injury, the type of year he's been having, the growth that he's had over the last couple of years and even this season - forget basketball, as a friend, as a little brother, it's hard to see anybody go through that but to see him deal with that, it's tough.

"It's tough to see and tough to watch."

Anthony suffered an injury of his own, leaving the match against the Warriors after six minutes with an ankle sprain. He is questionable for Thursday's encounter against the Los Angeles Lakers.