Sports information director Kent Brown said Wednesday that the sophomore will not play this season. Interim coach Bill Cubit has said for weeks that it was unlikely.
Junior receiver Justin Hardee could still also seek a redshirt though no decision has been made. Hardee broke a bone in his foot last summer and has yet to play.
Both were expected to start for the Illini (4-3, 1-2 Big Ten).
As a freshman last year, Dudek led Illinois with 76 catches for 1,038 yards.