High-profile Golden Slipper candidate Astern is on target to run well in the $3.5 million race after being the star turn in a Sydney barrier trial session.

Astern gave his six rivals a galloping lesson over 800m at Warwick Farm on Thursday, winning by four lengths under Godolphin jockey James McDonald.

Scratched from the Todman Stakes last Saturday because of an elevated white blood cell count, Astern clocked 47.4secs, equal fastest of the morning for two-year-olds.

McDonald said he asked more of the Silver Slipper Stakes winner than he usually would in a barrier trial.

"I did a little bit on him for the sake of him having missed that run," McDonald said.

"He trialled as well as a good horse could trial. If you put the top five market horses (for the Golden Slipper) in the trial they would have all done the same."

Astern shares the fourth line of Golden Slipper betting as an $11 chance with one-time favourite Capitalist.

Blue Diamond Stakes winner Extreme Choice heads betting at $2.80 over stablemate Flying Artie.

In other Warwick Farm barrier trial results, the Paul Messara-trained Scissor Kick has won a 1200m heat featuring the Caulfield Cup winner Mongolian Khan.

Scissor Kick led and ran away to win by almost eight lengths while Mongolian Khan sat at the back of the field.

Mongolian Khan didn't pass a runner but apprentice Travis Wolfgram kept the four-year-old going well beyond the finishing post.