Officials tell au.fourfourtwo.com that as of lunchtime, standing room only tickets have been released to the public are expected to be snapped up this afternoon.

"The interest from the local media has been huge... it's looking like a sellout," said Dom Rinaldo, Reds media manager.

United take a 1-1 draw into tonight's game. A 0-0 draw will see the A-League side through on the away goal rule, but coach Aurelio Vidmar does not have that mindset.

Vidmar said the quarter final was 'still in the balance' and added his team would still be playing for a win rather than a draw.

"You can't play for a 0-0 draw because once you set yourself up like that and you go a goal behind, it's very difficult to break that mindset and try to get forward," he said.

"If we can play as we did (last week), up to that level, then I'm very confident that we can get a result."