"I'll be surprised if he returns this season," Popovich said, according to the Express News' Jabari Young. "We only have X number of games left in the season and he's still not ready to go. And if by some chance there is, it's going to be pretty late into the season."
While Popovich wouldn't offer a definitive cutoff date, he added: "I'm just trying to be honest and logical, I'll be surprised if he gets back this year."
Leonard hasn't played since Jan. 13 due to a quad injury. Before that, he played eight games this season and didn't suit up for more than two in a row. The quad issue dates back to the preseason, and in November, Popovich said he'd "never seen an injury like Leonard's."
The Spurs have 23 games left and currently sit in third place in the Western Conference. San Antonio still ranks second in the NBA in defensive rating but has a tough schedule upcoming with road games in Denver, Cleveland, Golden State, Oklahoma City, and Houston.
The last time the Spurs won less than 50 contests in an 82-game campaign was in 1996-97.