According to Allonzo Trier himself, he will be able to play for the Arizona Wildcats again once the level of a banned substance in his system drops below the threshold that the NCAA considers illegal. This is the case because he won an appeal where he convinced them that he unknowingly took the banned substance.
On the surface, it sounds ridiculous, but it’s something that has happened with the NCAA before.
Back in 2010, Georgia offensive lineman Kolton Houston tested positive for the steroid Norandrolone (the drug Trier tested positive for has not been divulged).