An untimely setback derailed Annabel Neasham's Golden Slipper aspirations for Castanya, but a victory in the $1 million Percy Sykes Stakes at Randwick would be a handy consolation.

The winner of the Listed Lonhro Plate in February, Castanya's carnival was interrupted by a foot abscess, putting Neasham on the back foot to qualify her for a Slipper start.

The filly had a final throw of the dice in the Magic Night Stakes at Rosehill a week before the juvenile showpiece but came up short, finishing fourth to Saturday's rival Drifting.

"It was only a foot abscess, but it was a pretty big one and she missed a bit of work, so it wasn't an ideal lead-up into that race at Rosehill," Neasham said.

"She didn't enjoy the track that day and was a bit slow away, but she closed quite well late.

"She's got to be at the top of her game to win a race like the Percy Sykes, but she is a stakes-winning two-year-old, she won a Slipper lead-up and she deserves her chance.

"I've got a big opinion of her, and I think she has improved on what we've seen so far."

Neasham will be shooting for back-to-back wins in the Percy Sykes Stakes (1200m) after claiming it with Kristilli 12 months ago.

The trainer is also set to have a strong hand in the Arrowfield 3YO Sprint (1200m) with Maurice McCarten Stakes runner-up Libertad and talented filly Learning To Fly.

A dual Group winner, Libertad found his best form second-up when runner-up to Red Card then had genuine excuses for his last start flop.

"He was very good two starts ago then he got pole-axed twice last start and was lucky to stay on his feet," Neasham said.

"I just hope with him that he's got confidence.

"He's got the ability to win an Arrowfield. He quite likes it with a bit of juice in the track as well so if it's still like that on Saturday it will help him."

Neasham is still mulling over whether to run Learning To Fly from barrier 14 or go straight to the Robert Sangster Stakes (1200m) in Adelaide in a fortnight.

The filly was scratched from Randwick last weekend due to the heavy track, leaving Neasham in two-minds about the best way forward.

"I didn't feel the need to run her. As it transpired, the track raced better than I thought so I might not have pulled the right rein there," Neasham said.

"But the Group One is the aim with her on the 27th of April down in Adelaide.

"She's a high-quality filly, she is already a Group Two winner, so the Group One is what we really want to get with her."

Canberra Guineas placegetter Port Lockroy rounds out Neasham's Randwick team in the South Pacific Classic (1400m) but will have to overcome an outside draw in barrier 17.