The two new A-League franchises will meet in a pre-season friendly at United's home ground and although the gate has been capped at just 5,000, not all tickets have been sold.
Sims believes that there will be many who will show up on game day to purchase their tickets.
"I think a lot will turn up off the cuff. It will be a spur of the moment thing -- and they'll turn up with their mates and get their tickets at the door," he said.
"It's a male thing; we always leave things to the last minute.
"You might not get the full 5000 for a midweek game against the Fury, especially with the weather not the best, but I'm sure they will come reasonably close."