As the bloodstock adviser for international operators Qatar Racing, David Redvers is familiar with travelling horses around the world.

The UK-based operation, owned by Sheikh Fahad and his brothers, have thoroughbred interests in Europe, Australasia, America and Japan, and among them is Saturday's Queen Elizabeth Stakes contender Buckaroo.

A dual Listed winner overseas, the five-year-old is in his second Australian preparation, his best local effort a third behind Chris Waller-trained stablemate Via Sistina in the Ranvet Stakes (2000m) two starts ago.

Via Sistina was dominant at what was her Australian debut, but Redvers warned it wasn't easy for recently arrived horses to continue on that trajectory.

"It's very difficult to follow up after a first run off the plane," Redvers said.

"She is in very good hands to do so, but if we're going to beat her, I think this is our best chance.

"He's a horse that has been here a while now, so he's had time to acclimatise, which is obviously always a concern for the horses from the north."

Buckaroo will be one of four Queen Elizabeth Stakes (2000m) runners for Waller, who has won the $5 million feature five times, a trio of those with the incomparable Winx (2017-19).

However, three of the past four renewals have gone to William Haggas-trained international raiders Addeybb (2020-21) and Dubai Honour (2023), and while Haggas won't have a presence on Saturday, Waller has taken a leaf out of the UK horseman's book.

As Redvers pointed out, many internationals can perform fresh off the plane but don't always back it up, however Haggas' three wins came with horses who finished first or second in the Ranvet Stakes then had a three-week break en route to capturing the Queen Elizabeth.

Waller has used the same formula with Via Sistina and bookmakers are anticipating the same result with the mare a $2.30 favourite.

His other three runners are at double-figure odds with Buckaroo a $21 chance while Kovalica and Lindermann , who are backing up from unplaced efforts in the Doncaster Mile (1600m), are $23 and $26 respectively.

Waller said Via Sistina had continued to please the stable and didn't expect her Ranvet performance to be a one-off.

"I don't think she went to a new level, but she simply showed a touch of her European class," Waller said.