The multi-format series began with defending champions Australia clinching a narrow two-wicket victory with five balls to spare at Allan Border Field.
It is a sizeable setback for the tourists, who defeated Australia en route to World Cup glory earlier this year and recently replaced their arch rivals atop the International Cricket Council rankings.
Shrubsole admits the memory of their march to glory on home soil earlier this year could provide inspiration Down Under but refuted suggestions of lingering after-effects.
The 25-year-old seam bowler, who took 6-46 in the memorable World Cup final victory over India, said: “Everyone’s pretty fresh and raring to go. It has been a really long summer but if you can’t get up for an Ashes series when you haven’t got the Ashes then there’s something wrong.
“What happened in the World Cup can give us a huge amount of confidence coming out here, but, equally, we know that it counts for nothing, it’s a completely new series in different conditions.
“I know we snuck ahead of Australia but it was by the smallest margin possible so we always knew it was going to be a tightly fought series. The first game showed that and I’m sure it will continue all the way through.”