Ballage, 6-foot-3, 230 pounds, flew with the Sun Devils to Houston Thursday for their game against Texas A&M but had to be sent home prior to Saturday's kickoff after details of his illness became known.
Mono can lead to an enlarged spleen, which would likely extend the amount of time Ballage is kept off the football field and potential even result in it being a season-ending illness.
As a freshman, Ballage had 42 carries for 126 yards and three touchdowns and six catches for 64 yards and one touchdown. He was cited by ASU coach Todd Graham as the most improved player on offense during the spring and continued to impress through preseason preparations. In August, he appeared on the verge of being a breakout player for ASU given his rare combination of size and speed.
Now, it remains to be seen what the Sun Devils elect to do.
Junior De'Chavon Hayes had seven carries for just six yards in ASU's 38-17 loss to Texas A&M in Houston Saturday, backing up Richard. Some of those carries undoubtedly were scheduled to go to Ballage, but his late unavailability forced ASU offensive coordinator Mike Norvell to adjust immediately before the game.
The Sun Devils could elect to have Foster split time between wide receiver and running back, though that could lead to more uncertainty at the wide receiver group.
Another option for ASU is getting true freshman Jason Lewis, who is 6-foot-3 and 245 pounds, ready to play in coming weeks.