I did some researching and I think it's based on these two criteria:

2. The injury or illness occurs prior to the completion of the first half of the playing season that concludes with the NCAA championship in sport and results in incapacity to compete for the remainder of that playing season; and

3. The injury/illness occurs when the student-athlete has not participated in more than two contests or dates of competition, or 20% of the institution's completed contests or dates of competition in the student-athletes sport (whichever is greater.)

(So, the Irish would have until the 20% mark to pull the trigger on this, much like Mik Vaughn.)