Australia's Derby-winning performance (above) has been rated the equal of Sea The Stars' in 2009 with an official handicap mark of 123 for his Epsom display on Saturday.

That is inferior to the 124 rating handed out to Aidan O'Brien's 2012 Derby hero Camelot but the British handicapper stressed yesterday that such marks can change quickly as the season progresses.

"We have decided to give Australia a rating of 123, the same as Sea The Stars achieved after he won the Derby," said Dominic Gardiner-Hill. "However, as has been the case in previous years, that rating could go up or down, based on how horses that finished behind him perform in the future."

He added: “Workforce’s Derby performance was initially rated 128 before being downgraded to 125 and Camelot was given 124 so their Derby performances were considered superior to Australia’s.”

“It sounds as though Australia and Kingston Hill could go to the Curragh, which would be great. Based on the way Australia travelled and where he came from in the race on Saturday, I would expect him to come out on top again,” added Gardiner-Hill.

Australia has been made a 1/2 favourite with some bookmakers for the Irish Derby at the end of the month but his trainer has more modest fare on his mind today when Shield lines up in a €15,000 handicap hurdle at Roscommon.

This could be a more suitable pot for the other JP McManus-owned runner Give Me A Break, 9lb higher in the ratings for a Tipperary win last time, but still bottomweight today.

Shutter Island can be another McManus winner in the opener. Disappointing in a flat race on his last start, if Shutter Island runs up to his 107 jumping rating then he should be tough to beat.