
"Coming back in distance is the big query," Waller said.
"We want to switch him off and get him to relax because in three weeks' time he's likely to head to New Zealand for a million-dollar race.
"At his last two runs we've learnt nothing. One was a heavy track and he lead and last start he beat a three-horse field, where he did everything right, but I am not sure how strong the opposition were.
"He will get a true test here. We'd like to ride him a bit more conservatively from the outside gate and get in behind a few if we can."
Hugh Bowman will partner Scream Park (image Steve Hart) on Saturday in the A$100,000 contest for which he is a $3.20 favourite in the early market.