fact of life in college sports - Seniors graduate, and your very best players will often leave early for the professional ranks.
I choose to look at this game as a preview of coming attractions - a chance to see whether some of the backups have the potential to become solid contributors.
as far as the players listed - 1 OL, 1 WR, 1 LB, 1 DE and 1 CB.
5 out of 22 starters. yes, they are all solid players - but if this cripples the team, then IMHO the coaching staff has failed to recruit and develop backups who are capable of playing in the event of an injury or other situation - like an opt-out. The Gophers have over 100 players on the roster. I would hope that more than 22 of them are good enough to play.
and from what I've read/heard, Virginia Tech has been hit much harder by the portal and opt-outs - not to mention the fact that VA Tech recently fired several coaches.
the Gophers are not facing some juggernaut. this is a very winnable game - even without the players who have chosen not to participate.