This weekend is shaping as a pivotal one for the Melbourne Cup hopes of several internationally-trained gallopers.
There were 19 European-trained horses still in the running for the Caulfield and Melbourne Cups and one in the Cox Plate after Tuesday's first declarations for the three races, but that number could significantly dwindle this weekend.
Already, the rate of attrition has seen overall numbers for the Melbourne Cup down from 297 to 167, 292 to 136 for next month's Caulfield Cup, while 68 dropped out of the Cox Plate leaving 104 for the weight-for-age event.
A quarantine inspection of Aidan O'Brien's stables and the running of the Irish and English St Legers will all paint a clearer picture on which European-trained stayers make the trip to Melbourne.
As it stands, O'Brien leads the international raid on the Melbourne Cup with six horses, ahead of Godolphin trainer Saeed bin Suroor, who has three runners, and Luca Cumani, who has two.
But O'Brien's participation in Melbourne's spring will hinge on an Australian Quarantine Inspection Service inspection of his Ballydoyle stables on Friday (Irish time).
If AQIS is not satisfied O'Brien's facilities do not fall in line with tougher bio-security measures following last year's EI outbreak in Australia then the Irish trainer is likely to abort his trip to Australia.
AQIS wants O'Brien's Australian-bound stayers to be separated from the rest of his team but that would also deprive them of access to galloping facilities which would impact negatively on their preparations for the Melbourne Cup.
Cumani, whose stayer Purple Moon came second in last year's race, has paid up for Bauer and Mad Rush in both cups as did Godolphin with All The Good.
Godolphin also has Folk Opera and Schiaparelli in the Melbourne Cup.
Jane Chapple-Hyam, the daughter of former Liberal leader Andrew Peacock, left Yellowstone in the Melbourne Cup and could also have Cox Plate runner in Traffic Guard.
Traffic Guard justified a ticket to Australia with his second in the Irish Champion Stakes over the weekend.
Others remaining in the Melbourne Cup are French pair Orion Star and Varevees, British duo Bulwark and Sushisan, the Dermot Weld-trained Profound Beauty and South African stayer Mourilyan.
This weekend's English and Irish St Legers will be pivotal for many of the European chances.
Yeats, Septimus, Yellowstone and Profound Beauty are all engaged in the Irish St Leger, while O'Brien's trio Alessandro Volta, Washington Irving and Bashkirov, all three-year-olds under northern hemisphere time, will run in the English classic.