Enable and Magical look set to clash for the fourth time after Coolmore paid a late entry for the latter in the Yorkshire Oaks.
Seven fillies remain in contention for Thursday's mile-and-a-half (2400m) contest, with the prospect of taking on Enable not appealing to many.
Trainer John Gosden has also left superstar Enable in the Juddmonte International on Wednesday, but nominated the Yorkshire Oaks as his preferred route towards her bid for an unprecedented third Prix de l'Arc de Triomphe.
There is little between Enable and Magical on form, but to date Enable has come out on top all three times they have met, although the last two times, in the Breeders' Cup Turf and the Eclipse, the O'Brien-trained filly has got within three-quarters of a length.
Gosden holds a strong hand with Oaks winner Anapurna remaining in the mix, although she could wait and head to France for the Prix Vermeille, and Lah Ti Dar also in contention.
O'Brien has left in South Sea Pearl.
Sir Michael Stoute decided to take Sun Maiden out of the Prix Jean Romanet this weekend with the prospect of a race closer to home, while Ralph Beckett's Manuela De Vega, no match for Enbihaar at Goodwood, completes the list.