Johnson was suspended late last year and indefinitely last month by head coach Al Golden, who said at the time that he was "hopeful" the linebacker would return.
But it appears now that Johnson's future with the program is in major doubt.
The 6-foot-1, 238-pounder earned freshman All-American honors after leading the Hurricanes with 7 1/2 tackles for loss in 2012. He was fourth on the team in tackles with 59.
While Johnson was a rising talent, the Canes should still be fine at linebacker this fall. They return most of the players at the position, including second-leading tackler Denzel Perryman.