Rasa Lila was freshened after finishing fifth, beaten 2.7 lengths, in the Livamol Classic (2040m) on October 1, when unsuited by a slow track.
"She kept coming [in the Livamol] but couldn't show her best in the conditions," Ramsay said. "She's got an explosive sprint when she's right."
A better guide to her Captain Cook prospects would be her close third in the Windsor Park Plate (1600m) at Hastings, beaten a long head and half a head, behind Kawi and Mime.
The 6-year-old Darci Brahma mare won the Cuddle Stakes (1600m) at her last appearance at Trentham and last term also won the Travis Stakes (2000m) at Te Rapa and was a luckless third in the Manco Easter (1600m) at Ellerslie.
"We are really pleased with her at the moment," Ramsay said. "She's a bit stronger now and is a happy horse and enjoying life. She goes well fresh and will be suited by a big track at Trentham.
"She had a really quiet trial the other day, with Julia riding her, just to give her a day out and she went well." The Captain Cook will also serve as Rasa Lila's leadup to the Zabeel Classic (2000m) at Ellerslie on Boxing Day.
A good-quality field is expected to tackle the Captain Cook, with Volkstok'n'barrell, Abidewithme, Hasselhoof and defending champion Julinsky Prince among the other contenders.
Rasa Lila will be accompanied contest the $20,000 special conditions maiden 1600m.
Seraphim, a Rip Van Winkle mare from the Caulfield and Melbourne Cups winner Ethereal, easily won a maiden 1400m at Avondale at her last start.
The stable will also have two runners at Ellerslie on Saturday, with Mopsy contesting the rating 65 2200m and Sopraffina tackling the rating 75 2200m.
Sopraffina, a half-sister to Victoria Oaks placegetter Eleonora, raced below expectations at her last start but a subsequent blood test suggested that she had been off-colour.