History may turn out be a more formidable obstacle for It's A Dundeel than any challenge his remaining seven Rosehill Guineas rivals can mount today after the defection of Fiveandahalfstar from the classic.
Trainer Anthony Cummings made a Guineas call on Fiveandahalfstar earlier than expected, scratching him yesterday from a race in which he was a clear second favourite.
Fiveandahalfstar will now head towards next week's BMW with Cummings saying he has got his timing right for the weight-for-age staying test.
"Once I decided to gallop him today it put tomorrow out of the question," Cummings said yesterday.
"I am thinking his gallop this morning and another one on Sunday will probably get him to where he needs to be without having to worry about running on Saturday."
In Fiveandahalfstar's absence, It's A Dundeel promises to start one of the shortest-priced Guineas favourites since the race was shifted to an autumn date in 1979.
He was already at a red-figure quote with Fiveandahalfstar in the field but is now in rarefied territory as a $1.45 chance to emulate Metal Bender's Randwick Guineas-Rosehill Guineas double of 2009.
However, odds-on favourites have a chequered history in the race, none more so than Dignity Dancer, who was sent out at $1.50 in a small field only to succumb to Sky Heights in 1999.
It was an even worse result for the only odds-on runner since, with Universal Prince ($1.80) finishing midfield in 2001.
Craig Newitt is one rival jockey who isn't conceding the Guineas is a one-horse race as he returns from suspension to ride Hvasstan, now $7 second favourite in the TAB's reshuffled market.
"I've got a lot of time for him," Newitt said. "My first ride on him was in the Australian Guineas where he was the best run in the race by 100 yards, and then he came out and franked the form by winning the Alister Clark. All reports are he's improved again."
Hvasstan finished two lengths in front of It's A Dundeel when they met for the only time in the Victoria Derby, a result that has Newitt entertaining the prospect of a Guineas upset as confirmation of the horse's Australian Derby chances.
The other New Zealander in the Rosehill Guineas, Sacred Falls, is still to justify his lofty reputation in Australia but trainer Chris Waller is adamant he will.
Unbeaten in six starts in his homeland, the colt has finished fifth at his only two Australian runs in the Royal Sovereign Stakes and Randwick Guineas.
"He's had no luck in Australia," Waller said. "First up, he struck a wet track which he didn't appreciate, he can't quicken on it. He's got a massive turn of foot that we've seen only in trackwork in Australia.
"Second up, he got cannoned into at the 1400m mark and he was four-wide from that point through no fault of our rider."
The rider that day was Corey Brown, who warmed the saddle for regular partner Leith Innes.
Innes chose to remain in New Zealand where he won the Oaks but he is travelling to Sydney this weekend.
Perhaps the biggest query over Sacred Falls' Guineas chances is whether he will run a strong 2000m.
The race will be his first test at the distance but Waller doesn't see it as an issue. "He's won a mile group one race in New Zealand, which, I think, is a tough mile. They race with pressure on all the way."
Later on the card, the queen of Australian racing teams up with the Queen of England with Carlton House.
Carlton House, who will make his Australian debut for trainer Gai Waterhouse in the Ajax Stakes (1500m), is the first horse the Queen has had permanently trained in Australia.
Group one placed in the 2011 Epsom Derby and last year's Prince of Wales' Stakes won by So You Think, Carlton House will compete in the Queen's racing colours - purple with gold braid, scarlet sleeves, black velvet cap and gold fringe.
Carlton House is one of three $7.50 equal favourites for the Ajax, along with Havana Rey and Lightinthenite.