Playing a suspended player is totally different as the suspension is a punishment. Is Ji being punished for going out on loan or being Korean?
Of course, it's Gus so the book should be thrown at him!!
It does seem very petty having got internation clearance for a player, that if you let him go out on loan, you need to get clearance for a second time. That is down to the club secretary (who has now left the club) rather than any manager.