The question of whether to race Tougher Than Ever on a seven-day back-up is almost as difficult as where to do it.
The three-year-old put up a stirling performance against older horses in appalling conditions to run second to surprise winner Alma's Fury in Saturday's Apollo Stakes at Warwick Farm.
Trainer Chris Waller's options include Saturday's Australian Guineas at Flemington and the Hobartville Stakes at Rosehill.
"He's still in the Australian Guineas but if we went there he would come up against All Too Hard," Waller said.
"If we go to the Hobartville he has to take on Pierro. Either way it's hard.
"I'll see how he is over the next couple of days whether we decide to back him up at all or wait three weeks for the Randwick Guineas."
John Hawkes has confirmed the intention to run All Too Hard in the Guineas at Flemington a week after his second successive Group One weight-for-age win in the Futurity Stakes.
All Too Hard inflicted the first defeat on the Gai Waterhouse-trained Pierro in the Caulfield Guineas in the spring.
Pierro hasn't raced since his third behind Ocean Park and All Too Hard in the Cox Plate.
He missed a raceday gallop at Warwick Farm due to the weather but worked well on Saturday morning.
A Group One winner as a two-year-old in New Zealand where he raced as Warhorse, Tougher Than Ever was sent to Waller for an autumn campaign with a view to moving on again to Singapore where his owner Tang Weng Fei lives.
"The plan is for him to go to Singapore for their Derby where they run as four-year-olds," Waller said.
"The owner lives there and it would be great to get an Australian Group One win before he goes and would also be good for his future stud value."