The Phoenix have lost all three league encounters against the Sky Blues this season, but Herbert feels Sydney will be on a "downer" after their narrow defeat to rivals Melbourne in a two-legged major semi-final last weekend.

Confidence at the Phoenix is sky-high after their 3-1 extra-time win over Newcastle, and Herbert reckons his team's struggles against Sydney are now in the past.

"Maybe they are a little bit on a downer, maybe they have to change what they are doing," he said.

"They are at home and can be confident, but I think it's our time to change the outcome.

"It's different territory now. I think there's enough incentive for us to go across there and win, but we are under no illusions what Sydney will throw at us."

With his team in such good form, Herbert is facing some good selection headaches going into the match.

One of those is Brazilian forward Daniel, who is keen on a starting role after his eye-catching display off the bench against the Jets.

Young New Zealand striker Costa Barbarouses is the unlucky player to make way for returning defender Jon McKain.

Herbert must decide whether to restore McKain to the starting line-up or keep Ben Sigmund as skipper Andrew Durante's central defensive partner.

Sigmund struggled against Sydney striker Alex Brosque's pace earlier this season. NZPA