Chepstow's meeting on Monday is subject to an 8am inspection on raceday morning.
Officials at the Monmouthshire venue must assess conditions as parts of the course are waterlogged.
The situation has been compounded by 10 millimetres of rainfall on Saturday evening.
Clerk of the course Keith Ottesen said on Sunday morning: "It's heavy enough, and there is a bit of water around this morning - it's almost like winter ground.
"It needs to improve, but the forecast is favourable."
