Llewellyn is expected to undergo surgery in early January.
"Although this is not how I imagined my season here at Michigan would end, the support and love from everyone in the program will help me get through the rehab process," Llewellyn said. "I'm looking forward to being my teammates' biggest supporter for the rest of the season. Go Blue!"
Llewellyn, a 6-foot-2 guard who transferred to Michigan from Princeton last spring, had started all eight games for the Wolverines this season. He was averaging 7.0 points, 3.3 rebounds and 2.8 assists after putting up 14.0 points in three seasons at Princeton.
"We are devastated for Jaelin," Michigan coach Juwan Howard said. "He worked so hard after joining us this summer and was making that next step in leading this team. His maturity and work ethic has already made a mark on our program and culture. Knowing him, this setback will only serve as an opportunity to grow as a person and player, but more importantly, offer himself a chance to help this program in any way he can. I admire that."
The injury likely means an increased role for freshman point guard Dug McDaniel, who has been a consistent bench piece for Michigan through the first month of the season. The former ESPN 100 recruit is averaging 4.1 points and 2.1 assists.
Michigan (5-3) plays at Minnesota on Thursday in the Wolverines' Big Ten opener.