John O'Shea has given Sea Siren his tick of approval after watching the classy sprinter in a crucial gallop in Hong Kong ahead of Sunday's International meeting.

O'Shea only arrived in Hong Kong late on Monday and described Sea Siren's gallop on Tuesday morning on the Sha Tin course proper as "very pleasing".

Sea Siren is a leading contender for the Hong Kong International Sprint (1200m).

"To the eye her work was very pleasing and she wouldn't have blown a candle out afterwards so we know she's in good shape," O'Shea said.

O'Shea said the mare had enjoyed her time in Hong Kong and was confident the four-year-old would be hard to beat.

Sea Siren won the Manikato Stakes first-up before finishing second to Mental in the Group One Patinack Farm Classic down the Flemington straight last time out.

"She's been set for the race and with her brilliant gate speed, the 1200 metres around the bend is ideal for her, probably more so than the straight course," O'Shea said.

Australia's other International day representative is Alcopop who also worked on the turf at Sha Tin on Tuesday with jockey Craig Williams pleased with the hitout.

Alcopop will line up in the Hong Kong Cup (2000m).

"I didn't want him to do any more than slot into a nice rhythm and teach him where the winning post is," Williams said.

"He felt very sharp and he was very comfortable going this direction."