Sunday's meeting at Fontwell will have to pass an 8.30am inspection on Saturday if it is to go ahead.
The track is currently reported to be waterlogged in places following 17 millimetres of rain on Friday.
Further rain is forecast, both on Friday and Saturday, prompting officials to assess their prospects of racing.
Friday's Chepstow fixture had to be abandoned due to a waterlogged track.
Officials had planned to inspect the course at 8am due to the threat of further overnight rain on already heavy ground.
However, following a further 13 millimetres of rain, that check was brought forward and the meeting was called off.