A total of 12 horses have been declared for the King George VI And Queen Elizabeth Diamond Stakes but the final field for the midsummer highlight may not be known until much closer to Saturday's contest.
Due to the prevailing fast ground at Ascot doubts surround several of the leading contenders including long-time ante-post favourite Sakhee.
Godolphin's Prix de l'Arc de Triomphe winner is joined in the Stg£750,000 midsummer showpiece by stablemate and Prince Of Wales's Stakes hero Grandera.
Sheikh Mohammed's team have also declared likely pacemaker Narrative. A decision on Sakhee taking part is set to become clearer tomorrow.
Godolphin's jockey Frankie Dettori told attheraces: "Basically until we arrive there on Friday and have a look at the ground then, no decision will be made.
"I'm in the dark as much as the punters and everybody else.
"Both horses are in top form and ready to go _ now it's down to the ground and see how Ascot rides on Friday."
Clerk of the course Nick Cheyne said: "We are going to put a little bit more water on today. We missed the rain all yesterday and last night.
"The forecast is then to stay dry through Friday, Saturday and Sunday.
"It's safe fast racing ground."
Heading the opposition is Marcus Tregoning's Dubai Champion Stakes winner Nayef, along with Sir Michael Stoute's Golan and the Mark Johnston-trained Zindabad.
Tregoning has also got Sir Effendi in the 12-furlong contest, ensuring there will be shortage of pace.
Henry Cecil has left in High Pitched, although connections would like to see some rain, a comment which also applies to John Dunlop's Millenary.
"If the ground is firm, I just can't run him," Cecil told the Independent.
"He's very talented but on fast ground he saves himself. He's a 10lb better horse with cut."
Storming Home represents Barry Hills, while foreign flavour is added in the shape of Vodafone Coronation Cup winner Boreal, and Aquarelliste, runner-up to Sakhee at Longchamp.