O'Brien's pair of Johannes Vermeer and The Taj Mahal are joined by Riven Light, who endured a largely disappointing novice campaign over hurdles last season, but has been reinvigorated by a switch to the Flat this summer.
Since bolting up in the BMW Mile at the Galway Festival, Rich Ricci's gelding has won at Tipperary and in a Listed prize at Listowel and steps up to top-level company this weekend.
Mullins' assistant David Casey is in Australia to oversee preparations for the team's four-strong team, with Wicklow Brave, Thomas Hobson and Max Dynamite all being lined up for the Melbourne Cup.
Of Riven Light, Casey told www.racing.com: "He's a very relaxed horse and takes it all in his stride.
"We've been very happy with his work. He's a little bit hairy, his winter coat is there and we might have to give him a clip after the race, but other than that we're very happy.
"It's going to be tough. It's a step up for him again.
"He didn't really take to hurdling. He won his maiden hurdle and then had a few indifferent runs, but when we brought him back on the Flat he started to improve.
"We hope there's a bit more improvement in him and the style of racing will suit, it's just whether he's good enough to take on the Group One horses or not."
Riven Light will be ridden by Glen Boss in the 10-furlong contest, which features 10 runners.
There is plenty of British interest in the supporting events with the Hugo Palmer-trained Wall Of Fire and Charlie Appleby's Kidmenever running in the Group Two Herbert Power Stakes while Jane Chapple-Hyam fields Kaspersky in the Group One Toorak Handicap.
Palmer's Mask Of Time is a reserve for that race and is also in the Listed Weekend Hussler Stakes earlier on the card.
