Bulldogs backrower Jacob Preston has described his call-up to the Australia Kangaroos squad as a moment beyond belief, admitting he was "lost for words" when coach Kevin Walters broke the news.

The 22-year-old is part of a 24-man touring group preparing for the Ashes series against England, with the first Test to be played at Wembley Stadium on 25 October.

Preston's inclusion caps a rapid rise for the hard-working forward, who finds himself in contention for a back-row starting spot alongside seasoned internationals Angus Crichton and Hudson Young.

Speaking to NRL.com, Preston said the selection marked the fulfilment of a lifelong ambition. "I was lost for words when Kevie told me I was in the squad," he said. "Just to be given the opportunity means so much to me. It's your goal as a kid wanting to play NRL, and the No.1 thing is to play for your country. I'm very grateful to be in the squad, but it doesn't mean you're guaranteed to play."

While competition for spots is fierce, with Walters juggling a wealth of options across the park, Preston's focus remains on contributing in any way he can. "If I do get the opportunity, I won't let anyone down," he said. "I'm keen to soak it all up and learn as much as possible."

The Kangaroos are currently in London for a 10-day preparation camp as Walters weighs up key decisions across the fullback, halves and back-row positions ahead of the highly anticipated Ashes opener.