Roar's preparation for their biggest game of the season will include a must-win midweek fixture against a top international opponent.

With a chance to win back-to-back Championships, Roar could be excused for showing caution or resting players in their clash with K-League big-shots Ulsan, who are undefeated in three ACL matches and lost just once in seven domestic matches so far this season.

But Roar skipper Smith insists a real match was a positive for the players and far preferable to what they'd be put through by their coaches in training.

"At the moment we're not focusing too much on the grand final on Sunday, it's all about trying to get three points against Ulsan at Suncorp tomorrow night," Smith said.

"We've been preparing for this moment for quite a long time and I'm pleased we do have a game, because otherwise we'd be getting smashed [at training] tomorrow.

"We've kind of gained momentum in the last few weeks because we've had the midweek game. In terms of routine, it feels like we should always have a midweek game now.

"I think it's more of a positive that we're playing as opposed to a negative and I think we can create some rhythm heading into Sunday as well."

Having taken two draws and a loss from their opening three ACL fixtures, a win on Tuesday is imperative for Roar – currently bottom of their group - if they are to progress to the second round of competition.

Despite having a major incentive to hold something in reserve for Sunday, coach Ange Postecoglou said Roar would stick to their playing mantra of relentless aggression and would even start 'under the weather' star striker Besart Berisha.

"I think they probably expect Australian teams to go over there and defend for 90 minutes and play a certain style, and we certainly aren't that," said Postecoglou.

"It's more the manner we play rather than the quality we play that have surprised Ulsan and Beijing in the last two games.

"That's what we're about, we want to try to show people we can play the brand of football that we play every week in the A-League against the best in Asia."