Despite St Covet's Spirit being no match for the exciting Rubisaki in the P J Bell Stakes, her trainer Jason Coyle saw encouraging signs in the filly's return at Randwick.

And while Rubisaki is the short-priced favourite again for Saturday's Group Three J H B Carr Stakes (1400m) at Randwick, Coyle is looking forward to seeing what improvement $41 chance St Covet's Spirit can show.

Coyle has thought highly enough of St Covet's Spirit to run her in four Group races for fillies so far in her nine-start career.

Her best performances was fourth in the Group One Flight Stakes (1600m) last spring.

St Covet's Spirit resumed from a spell in the Group Three P J Bell (1200m) on April 4 and settled back after a slow start before working home for fifth, beaten five lengths.

Rubisaki, who has seven wins from nine starts including five from five this season, was a convincing 1-1/2-length winner of the race and is $1.65 favourite to win again on Saturday in a field of 10.

"I thought she reeled off some solid sectionals late so she's obviously going to benefit from that run and I think she will really appreciate stepping up to 1400 metres," Coyle said.

"Rubisaki is obviously the horse to beat. She's a filly in outstanding form and looks like only having to probably turn up in the same vein of form to be very hard to beat.

"But we met her first-up over 1200 metres so I'd like to think she's got a bit of improvement in her and I think they'll know she's there on Saturday."

Coyle said St Covet's Spirit had always shown ability and was physically stronger than last preparation.

"The big thing with her is she's always struggled to probably relax a little bit," the trainer said.

"There were good signs first-up that she switched off straight away and she only has to switch off in the run over 1400 and I know she can be very strong late."

Jason Collett rides the filly with regular partner Kathy O'Hara in two weeks isolation ahead of a change of riding zones prompted by the COVID-19 protocols.