Humphries suffered the injury late in the fourth quarter of Wednesday night's victory over the Oklahoma City Thunder. He limped off with trainer Tim Walsh into the locker room with 1:36 left in the game.
Humphries, 27, is averaging 7.2 points and 7.3 rebounds in 27 games (20 starts) for the Nets (17-15). He recently missed five games because of a mild abdominal strain.
With Humphries, now a reserve, out, seldom-used forward Mirza Teletovic may play some minutes off the bench, according to the team's official Twitter account.
Backup point guard C.J. Watson will be in uniform, but will not play for a second straight game because of a bruised right knee. Rookie Tyshawn Taylor will once again receive minutes behind starter Deron Williams.