Friday night's Hyundai A-League clash with Perth Glory is the first of three games in eight days for the New Zealand side as it begins the run home to what it hopes will be a first appearance in the playoffs.

Following the match in Perth, Phoenix face a tricky match in Melbourne on Tuesday before playing cellar-dwellers Adelaide United in Christchurch on January 30.

"I think it is season-defining," McKain said of the fifth-placed side's road trip. "If we can pick up some results in these two games we can cement ourselves in the top six and take some pressure off us.

"We know there are five more games to come and we've got to play well. We're not taking anything for granted. We know the A-League will probably come down to the last game of the season as it has done recently.

"We know Perth are going to be coming off two tough trips this week and hopefully they will be a bit tired. We want to go over there and have a go at them.

"If we can put them under pressure early on then we can cause them all sorts of trouble."

Phoenix, on a three-match winning run, will be without one of their mainstays for the games against Glory and Victory with left-back Tony Lochhead remaining in Wellington to rest a niggling groin problem.

That has prompted a reshuffle in defence with centre-back Ben Sigmund expected to start in the less familiar right-back role and Troy Hearfield switching to the left.

Sigmund has not played since December 4 after sitting out three matches for punching Victory's Adrian Leijer, then being unused off the bench in Phoenix's two most recent wins.

The All Whites defender admits it has been a frustrating few weeks on the sidelines after playing virtually every game prior to his suspension.

"It's tough," Sigmund said. "The team has won three on the trot and as much as you want to say you want them to play bad so you can get back in you also want them to play good so they win.

"It has been frustrating, especially the last two weeks."

Hearfield has impressed since taking over from Manny Muscat at right back with his speed and attacking mentality earning him plenty of plaudits.

Sigmund, however, is aware that his strengths lie elsewhere.

"I can't go out there and pretend I'm a Troy Hearfield or a Tony Lochhead, I'm a bit more of a defensive player," he said.

"I think that will give the freedom for Troy to do his thing down the left or right-hand side and me and Jon McKain and Andrew Durante can be nice and solid at the back."

"The boys have been playing well. The pressure is on me to come in and do well because we want another three points."