The Western Australian outfit was sitting at the top of the table after five rounds but have dropped their past six matches and are now out of the top six.
Winger Todd Howarth was at a loss when trying to explain the poor run of form but was confident the players would be able to bounce back in the coming weeks.
"Training and preparation for games has been good," Howarth told WA Today.
"(But) we look a bit flat on matchday. I don't know the reasons for that, just maybe we're lacking a little bit of confidence at the moment.
"(Against Sydney) there were a few areas like not being able to hold the ball up in certain areas and pushing the whole team forward as a unit things like that.
"All the players want to win, we're just in a rut and obviously lacking a bit of confidence. Football's like that, if you get a few bad results, it's tough to get out of.
"It's difficult to cop results like that every week," he added.
"It is tough to look forward to the next week when you do get results like that but there's no point whingeing about it. You've got to get on with it, there's a good group of players here and I'm pretty confident we can get through it."