Team spokesman Derrick Burson confirmed Black's status Thursday.
Black had surgery on his right knee on Oct. 9 and has played limited minutes in just a handful of games since his return. He did not play in Illinois' two most recent games.
The 6-foot-7, 220-pound Black was expected to start this season and offer inside scoring, rebounding and defense to a team that is short on all three.
Black is one of three would-be starters out long-term for Illinois (6-5). Point guard Tracy Abrams is out for the season, and coach John Groce has said he isn't sure if center Mike Thorne Jr. will return.