Glory's back five in last week's 1-1 draw with Brisbane was completely different from the defensive set-up that took the field in last season's grand final loss to Sydney.

Alex Grant, Gregory Wuthrich, and Osama Malik formed the heart of defence against Brisbane, while Joel Chianese and Brandon Wilson were used as the wingbacks.

The quintet went within seconds of keeping a clean sheet, only for a late header from Roy O'Donovan to break the shackles.

Ivan Franjic, who was suspended last week, is expected to replace either Wilson or Chianese for Saturday's clash with newcomers Western United in Geelong.

Reddy was pleased by the early display from the team's revamped defensive unit.

"When you look at it from last season, it's a totally new back five from the grand final. They did extremely well and will continue to get better," Reddy said.

"I think our first 25, 30 minutes was some of the best football I've seen played here from my time at Glory."

Perth's defence will be put to the test against a Western United outfit featuring Besart Berisha, Scott McDonald, and Italian Alessandro Diamanti.

Berisha scored in last week's 1-0 win over the Phoenix in Wellington.

"With Berisha and McDonald and Diamanti, they look very dangerous," Reddy said.

"We're going to have to be at our best. It will be a good battle for us."

Australian Associated Press