But he doesn't know how many will not attend, the club will find out at half time on the day of the game when the turnstiles close. He will have to have the stewards in place regardless, a few threats of pitch invasions in the meantime won't hurt though.
Where have the sit-in protests been so far then? Nothing to stop you doing it up to now.
This is to show strength of feeling - and give him a good idea what if will look like next season when barely anyone buys a season ticket.