City has lost to Perth twice this season and drawn once in a succession of high-scoring games - 5-4 and 3-2 wins to Glory alongside one 3-3 draw, with the two teams having met in that bizarre nine-goal thriller in WA last week.

On the face of it this game looks balanced on a knife-edge, despite City having home ground advantage, so the first thing the City boss wants is for his team to focus for the full game - whether that be 90 minutes or the 120 minutes that might be needed should it go to extra time.

Then he wants his team to play to its strengths - its ability to switch from a 4-3-3 to a 3-4-3 to a 3-5-2 set-up - as the game develops and the tactical flow and circumstances change.

Valkanis pledged some changes in personnel too, but was playing his cards close to his chest on the eve of the match.

"There will be a couple of changes in regard to our set-up. Having played Perth three times this year we will set up with a slight difference.

"In all games we have had so much of the ball, we have been in attack that much, its like we switch off, either in the counter attack or set piece. Its something we have worked on again this week."

"We are unpredictable, they won't know what we are doing, 4-3-3, 3-4-3," he said.

Valkanis says that he has no injury worries - save for the players who have been out all season, Corey Gameiro and Steve Kuzmanovksi, and the out-of-action Fernando Brandan.

Tim Cahill was a crucial figure in Perth, scoring at a vital time to ensure his side fought back from a 4-1 deficit, and his big game know-how will be critical in such a tense encounter as a sudden-death elimination final.

Nick Fitzgerald, who came off the bench to good effect in WA and scored City's fourth goal, might be a chance to start on one flank instead of the disappointing Nicolas Colazo, while Anthony Caceres is also an option as an attacking midfielder.

Valkanis acknowledges that a lack of concentration at the back, despite good work in the rest of the field, has been costing his team.

"We want to stop conceding. We have probably had the least shots against us after Sydney [during the season]. We do some things really well, there are still some things that we need to get better at.

"It's [defending] a bit more complex than just sitting back and absorbing pressure."

Perth, he says, are fairly predictable in the way they set up even though City has not been able to crack the code against Glory so far this campaign.

"They are predictable, they are very physical as well. We have to match them and beat them physically as they bring a physical and direct game to the A-League."

Valkanis bridles at any suggestion that if City does not match its achievements of the past two seasons and make the last four the season will have been a failure.

"We have won the FFA Cup, we are in the finals, we have a chance to win silverware," he points out. "People have said we should be champions. We will assess at the end of the finals campaign whether it has been a success."

This is Valkanis' first final in charge of his own team, having been part of the coaching team with last year's title winners Adelaide. But the coach, who has spent a lifetime in the game, says that this match in isolation is not a particular test of his ability.

"I wouldn't say it's a test. It's part of football. I am happy that I am part of a club that looks for success. This is where you want to be, you don't want to be on holidays."