PERTH Glory coach Tony Popovic will demand 90 minutes of total concentration from his side when its faces reigning champions Melbourne Victory in Sunday afternoon’s A-League clash at AAMI Park.

Glory lost their way in a 20-minute second-half spell of their opening match last weekend that allowed Western Sydney Wanderers back into the game for a 1-1 draw.

They can’t afford to repeat that against a Victory side on the rebound from their first-round 2-1 loss in the derby against Melbourne City.

Popovic places a lot of emphasis on the mental concentration needed to win games and defender Shane Lowry admitted they had relaxed at a crucial time against Wanderers after an excellent first half.

“If you are mentally strong, it gives you a great chance of winning. It’s about switching on and staying alive for the whole 90 minutes,” Lowry said.

“That (goal) was their first shot on target which was disappointing but shows if you don’t concentrate for the full 90 you can get punished and that was the case for us. If you switch off for two minutes, they can score.

“You always want to improve the mental aspect of the game, when you’re tired, the weather, different aspects come into it.”

Glory, who have not beaten Victory at AAMI Park since their 3-2 win five years ago, will be without marquee signing and captain Diego Castro who has not recovered from a hamstring problem.

Defender Matthew Spiranovic comes into contention after missing last week but is expected to be among the substitutes and forward Chris Ikonomidis, who came from the bench for 25 minutes, may get more game time.

But Popovic is unlikely to make wholesale moves.

“It don’t think it’s about changes. It’s about us improving our game,” Popovic said.

“It’s an easy answer but there isn’t an aspect we can’t improve on.

“We had a period in the second half where Wanderers came into the game and we weren’t really at our best. But we recovered very well.

“Specifically, if we can keep creating the chances, that’s the important part. If we can do that again against a very good side in Melbourne then we give ourselves a chance to score goals.”

Victory played down a training-ground knock to Japanese star Keisuke Honda yesterday but will be without Swedish striker Ola Toivonen, who has a calf injury.