Promising sprinter Shiraz is unbeaten in heavy going but the wet Randwick track is still a concern for trainer Tony McEvoy ahead of the gelding's biggest test in the Concorde Stakes.

Shiraz has been freshened for Saturday's 1000m sprint at Randwick after winning the Group Three Aurie's Star Handicap (1200m) at Flemington a month ago.

The six-year-old is unbeaten in three starts this campaign, with two strong wins during winter in Sydney on heavy ground before a gutsy victory in the Aurie's Star.

Rain over the past 24 hours had Randwick in the heavy range on Friday.

"They tell me it's a heavy nine. I didn't quite expect that," McEvoy said.

"I'm not sure that that's ideal for him, and he's back to 1000 metres. It might help him in that sense. It's going to be a stronger 1000 than it would have been.

"He's trained on beautifully.

"It's his toughest test to date but he's been impressive in his three wins so far and he deserves to be in the field."

McEvoy said Hugh Bowman's opinion after guiding the sprinter to his win two starts ago was that he wasn't totally comfortable in the wet.

"Hugh Bowman, who won on him two starts ago, thought he wasn't that comfortable in the (heavy) track. And I respect what he says," McEvoy said.

Shiraz has built up an impressive winning record with nine victories from 14 starts, five of those wins since joining McEvoy from country NSW trainer Peter Nestor.

He is the second-elect at $3.50 behind Group Two winner Ball Of Muscle ($3.20).

Ball Of Muscle's Joe Pride-trained stablemate Craftiness is at $4.20.

McEvoy said The Shorts would be Shiraz's next start after the Concorde.