Michael Stoute's once-raced filly Liber Nauticus goes on trial for the Oaks in the Tattersalls Musidora Stakes at York on Wednesday.
The daughter of Azamour won a Goodwood maiden by a length and three-quarters in September and has been considered as a contender for the Classic ever since.
Indigo Lady represents Peter Chapple-Hyam and was third in a French Group Three at the end of last season.
John Gosden's Woodland Aria has a similar profile to Liber Nauticus having won a Wolverhampton maiden on her only appearance.
Richard Fahey's Romantic Settings is the mount of Paul Hanagan and Mark Johnston runs Discernable. Hollowina completes the field of six.