The sharpshooting 7-footer was injured with 6½ minutes to play in the fourth quarter of Sunday night's 122-118 overtime loss at Oklahoma City.
Frye had a career-high 15 rebounds in the contest, the last of the Suns' season-long six-game road trip. He had two game-winning shots on the trip.
The extent of the injury was confirmed in an MRI exam on Monday.
The former University of Arizona star has appeared in all 61 games for Phoenix this season, averaging 12.3 points and 6.6 rebounds.