The Pistons announced Wednesday that Hayes will continue to be evaluated by the medical staff, but no updates were made available on a timetable for his return. The team said an MRI performed Tuesday confirmed the diagnosis.
Hayes, 19, was drafted seventh overall by the Pistons last year and has started all seven games this season, despite averaging 4.6 points and 3.6 assists on 27.7% shooting. His points and minutes per game (21.1) ranked last among all starting point guards this season.
The latest injury report has Hayes listed as out for Wednesday's game in Milwaukee.
"It's tough, especially for a young kid to play seven games and be injured," Pistons coach Dwane Casey said before tip-off. "He's coming into the league just figuring it out, but he has to use that as a positive. Study film, sit down with the coaches, watch practice, sit during timeouts with the coaches and really be a student of the game, of the NBA game, and use this as a positive time to learn, to observe and really get as much as he can mentally while he's rehabbing and trying to come back."
Casey said he spoke to Hayes on Tuesday night, and Hayes' parents continue to stay with him in Detroit, hoping to keep his spirits up during this rough start to his career.
"He was like a typical 19-year-old, and I think he was down a little bit, but he'll be OK," Casey said. "Just trying to use this time as a positive."