Americain has been given top weight of 58 kilograms for the Emirates Melbourne Cup at Flemington on 1 November.
The Alain de Royer-Dupre-trained six-year-old shouldered 54.5kg when victorious in the race 12 months ago.
The top-three-weighted horses in this year's Melbourne Cup are all internationals, with Brian Meehan's Dangerous Midge on 57.5kg and Irish St Leger winner Jukebox Jury, trained by Mark Johnston, on 57kg.
Johnston also has Fox Hunt (53kg) entered.
Godolphin's Cavalryman has been allocated 55kg, with emerging stablemate Lost In The Moment given 53kg.
Red Cadeaux, third in the Irish St Leger, has 53.5kg, while David Lanigan's Meeznah, impressive in the Park Hill Stakes at Doncaster on Thursday, is the highest-weighted mare on 53kg.
Dermot Weld's entrants, Galileo's Choice and Sense Of Purpose, have received 52.5kg and 51.5kg respectively.
However, the former has yet to pass the first ballot, while Sense Of Purpose has been ruled out for the rest of the season.
Luca Cumani's Bauer (52kg), Melbourne Cup runner-up in 2008, has also yet to pass the first ballot.
Of the other internationals nominated for the Melbourne Cup only, the Brian Ellison-trained pair of Saptapadi and Ebor hero Moyenne Corniche both have 52kg and are not yet guaranteed a start.
Several runners have progressed in the weights for the Melbourne Cup as a result of victories since the release of the Caulfield Cup weights, including the Michael Stoute-trained Modun.
The four-year-old, who did not accept for the Caulfield Cup last week after being an original entry, has risen from 51kg to 53kg following victory in the September Stakes at Kempton.