But he expects all three to be highly competitive and hopefully kickstart a successful weekend.
Rocknroll Arden starts the night in the Oaks trial and even allowing for the class of her northern opponents she will be close to favourite after finishing second to Venus Serena in a national record 1:52.2 mile at Ashburton last start.
"She is a good filly and races well at Alex Park so she will go close, even though Snooki is a good filly and there is a bit of depth there," said Purdon.
He sends debut-winning juvenile Jay Dub north for the last heat of the Young Gun series, with the youngster having some historical pressure on his back.
He was bred by, and named in honour of, the late Jack Smolenski, one of harness racing's great trainers who had a spectacular record at Alexandra Park.
"He is a lovely horse, although probably not as advanced as my best juvenile Follow The Stars at this stage," says Purdon.
"But it looks like we have got him into a good heat for him and he can win providing he has some luck from that wide draw."
While both horses will have strong support, Purdon rates Bonechip in the last race his best chance of the night.
"He is actually better right-handed which is one reason he is up there," says Purdon.
"And with the small field he is going to be hard to beat."
Purdon will then turn his attention to Menangle tomorrow night where Willow and Isaiah need only to finish top five in their heats to qualify for the New South Wales Oaks and Derby respectively.
Willow is unbeaten but meets exciting Victorian filly Nike Franco so faces a big test, while Isaiah has drawn the weaker of the two Derby heats. "He needed his run at Addington last week and is ready for a good hit out this week before the Derby," Purdon says.
Purdon will take champion mare Adore Me to Addington for a private workout on Monday before she heads to Sydney with Smolda on Tuesday, where they will join up with tomorrow night's starters as well as Border Control. That should see the stable with five fancied runners in group one races worth A$1,550,000 on Sunday week.
Both Smolda and Adore Me have been nominated for the Auckland Cup so could return to Alexandra Park for the great race five days later.
"I will wait to see what happens on that Sunday before making that decision."
Smolda is shortened to be joint favourite for the A$750,000 Inter Dominion Final, for which the barrier draw will be held on Monday morning.
