Chase The Dream has played second fiddle to Lazarus in most of the major races this season but with that stablemate spelling you would think Saturday's final $150,000 race would be his chance.
But Purdon isn't so sure.
"It is not that we are unhappy with him and he looks good but he was only all right at the workouts last weekend," admits Purdon.
"Maybe he is still on the way back up after racing in Perth but I won't really know until I drive him in trackwork on Thursday.
"Those good horses can improve a lot in a week so I am putting a lot of emphasis on how his final fast workout goes."
Purdon says if Chase The Dream (barrier seven) at his peak had drawn inside Heaven Rocks (five) he would have been the stable's clear top pick but now Heaven Rocks may have a slight advantage. But that depends on whether Heaven Rocks behaves, after galloping twice and costing punters a fortune in his last four starts.
"I think he will be fine on Saturday but he has been a hard horse to train and is a hard horse to drive so there are no guarantees."
Purdon is equally confused, but for different reasons, about Saturday's other three-year-old pace, where the stable has the three favourites, all group one winners this season.
Dream About Me is the best filly in the country but has the worse possible draw at one on the second line, while Piccadilly Princess (two) and Golden Goddess (three) are set to control the race.
Over the punishing, rain-soaked 2600m of the NZ Oaks last start, Dream About Me was able to outstay her stablemates but a sprint around Cambridge gives her a lot less time to make up the expected deficit.
"To be honest, I can't pull back to last on her to get off the markers so I have to try and push through," says Purdon. "The horse we follow out, Killer Queen, has gate speed so we can keep going forward at the start but then a lot depends on the horses around her.
"Even if we do get off, if she has to give Golden Goddess a good start over a mile it is going to be very hard to catch her."
Purdon is playing down Spanish Armada's poor workout at Cambridge last Saturday, saying she is well but realises she is going to need a hot tempo to bring the likes of stablemate Partyon and Delightful Memphis back to her in the two-year-old Diamond.
And to further add to Purdon's, and punters', confusion both Pacing Major and More The Better face second line draws in the male juvenile pace.
"They are both very good and the one who gets in front of the other probably has the best chance," he says. "Maybe Pacing Major has the better draw because the horse he follows out is a quick beginner and he might be able to get away from the markers."
The four-year-old Emerald is down to 12 runners, with Prince Of Pops and Hank Bromac scratched, the latter's withdrawal allowing Tony Herlihy to driver Victorian My Kiwi Mate.
