Saturday's high-profile fixture at Ascot is subject to a precautionary inspection at 8am.
The Berkshire circuit staged a six-race card on Friday, but only after an impromptu inspection an 11.30am.
While the ground was expected to be heavy, there had been no problems anticipated until clerk of the course Chris Stickels announced the check mid-morning, with a delegation of track officials and several jockeys assessing conditions.
The meeting was eventually given the green light and took place in its entirety - but Stickels later felt it prudent to call a further inspection ahead of Saturday's card, which features Paisley Park's defence of the Grade One Marsh Hurdle, together with the £150,000 Betfair Exchange Trophy.
Stickels said on Friday afternoon: "Racing went ahead today after I found some marginal ground and we managed to get round that and racing went ahead successfully.
"There is further rain forecast, mainly showers, but six millimetres before racing is what I have been forecast.
"In light of further rain forecast, the sensible thing is to have a precautionary inspection and we will have it at 8am so we can see and get a clear picture of what has happened overnight and what it looks like in the light.
"It is a good draining track, but clearly we have had an awful lot of rain now. We have had nearly 60 millimetres since last Friday morning, so it is a huge amount of rain.
"I wouldn't know how much it could take with having marginal ground like this, as it can change very quickly."
Friday's all-weather meeting at Southwell had to be abandoned after four races following torrential rain during the afternoon.
Mark Clayton, executive director at the Midlands circuit, told Sky Sports Racing: "We've had an unprecedented amount of rain here since the middle of October and it has rained the majority of the day today.
"The sand is sodden, the water table is very high and there is standing water in plenty of places.
"It's a sad occasion today as it's the first meeting we've had to abandon this year. The team have done a magnificent job, but today was just beyond us.
"The last meeting we abandoned on the all-weather was on December 29, 2017. It's an all-weather surface and it lives up to its name the majority of the time."
