A-League leaders Western Sydney have been undefeated in the seven weeks since they last took on Perth, but midfielder Andreu has reminded the team of how fickle football can be.
The knives were out for Tony Popovic's side when they hosted Perth back in round 4 without a win their back pocket.
In the end it was Dario Vidosic's 45th-minute goal that was the difference in a dogged 1-0 win.
Andreu insisted the team had deserved the full three points, but he also remembered how close they went to opening the new campaign without a win in the first month.
"The win was deserved for us, 100 per cent. It wasn't easy," he said on Tuesday.
"When you are winning just for one goal the difference, always you have just one mistake, (and) you can lose the game or you can lose two points."
After dispatching of title contenders Brisbane and Melbourne Victory over the past fortnight, the Wanderers are expected to make short work of lowly Perth, who recorded their first win in five matches last weekend.
But Andreu said their meeting with the ninth-placed Glory was proof that their trip to the other side of the country wasn't going to be a holiday.
"Melbourne and Brisbane are doing well, but Perth Glory, we won just 1-0. It wasn't an easy game," he said.
"They have really good players. Maybe they are not at their best moment, but they won their last game. Of course, they are getting better."
The long flight will be just the Wanderers' second away match in five weeks, and second over a seven-week span where they can establish a big gap on the rest of the competition if they achieve home wins.