Cornish is a four-star guard from Maryland, attending high school in South Carolina.
Maryland has a number of alumni taking the field as the league returns to action.
Penn announced he would play at LSU.
Voluntary football workouts have been suspended.
The season is still due to start in early September despite the schedule change.
The former Maryland center had one of the more impressive games of the weekend.
Williams is the top-rated quarterback in the class of 2021.