Ricki Herbert is playing his cards close to his chest ahead of Wellington Phoenix's key clash with Adelaide United at Westpac Stadium on Friday night.

Having watched his men stumble to a disappointing 2-0 Hyundai A-League 2009/10 defeat to Sydney FC last weekend, Herbert knows a win at home against the Reds will require a big lift in intensity and application.

The Phoenix were uncharacteristically flat at the Sydney Football Stadium and Herbert could make several changes to his playing squad to find some spark at Westpac Stadium.

"We've set the scene from an intensity point of view at training this week and worked on some changes in personnel to see the reaction from the players," Herbert said.

"That reaction has been good. This is a competition where, if you're not operating at the level you're capable of, then you're vulnerable. All the sides this year have been exposed to that.

"We've got good depth and quality in the squad. The players understand there are no (selection) guarantees going into this match or any other and we'll make the final decision on the squad after final training at Westpac Stadium and make the decisions around what we feel in necessary."

Herbert said he was not averse to making tough calls when it came to selection, irrespective of the players involved.

"Some are made for tactical reasons and some are made based on performance, but you've got to make those calls. Sometimes you get it right, sometimes you don't, and I don't think there's a manager anywhere in the world that ever gets it 100 per cent right.

"Players need to seize their moment, back themselves and understand the reasons behind the chance they're given."

While Herbert will delay naming his playing squad till after the Phoenix's final training session, some changes have already been locked in. Back-up keeper Jonathan Gould makes way for the return of Mark Paston, who missed the Sydney match to be with his wife for the birth of their first child, while fullback Manny Muscat is away on international duty with Malta.

Young Aussie Reece Crowther started in goal at the SFS and turned in a big effort.

"Mark comes back into the squad, there's no reason not to bring him back," Herbert said. "I thought Reece had a commendable first-up performance, so we'll be taking that into account."

The Phoenix boss was more guarded about how he would fill the gap left by Muscat, with skipper Andrew Durante, Ben Sigmund and Vince Lia all chances to slot into right back.

"What I will say is that (defensive midfielder) Jon McKain will play in central defence."

Back at home after playing three of the first four rounds of the competition across the ditch, the Phoenix will seek to develop a sharper edge on attack at Westpac Stadium in a bid to back up the excellent 2-1 home win against Perth Glory in round two.

"I think against Brisbane Roar (1-1) away from home we showed good attacking signs, but we'll probably look at doing something similar in approach to what we took against Perth," Herbert said.

"The game against Sydney was just one of those days. We didn't go there to sit back and soak up the pressure but we never got on the front foot. The license is always there for the front group to attack and win games and that'll be the stance on Friday night."