Sandown has put in contingency plans to stage an all-chase card on Saturday should the hurdles track be unraceable.
Clerk of the course Andrew Cooper described the hurdles track as "vulnerable" with more rain forecast on Friday. Officials at the Esher venue will have a look at the course on Thursday afternoon as well as take into account the latest weather forecast before making a decision.
Entries for the three extra chases will close at noon on Thursday with a decision on the hurdles course expected by 3pm.
Among the four races over the smaller obstacles are the Betfred Mobile Sports Contenders Hurdle, for which entries include last year's Champion Hurdle hero Rock On Ruby and Christmas Hurdle winner Darlan.
"If you don't make a start with your plans it becomes too late further down the line. It's a necessary stage and timing of the process if we are to give ourselves a chance. Our first and foremost objective is to try to run the card as scheduled," said Cooper.
"As is always the case here, the hurdles course is softer and more vulnerable. We've had about eight millimetres of rain in each of the last two nights.
"The thinking and the planning has to take into account the forecast. If it was a dry week you'd be pretty confident of staging the existing card, but we've got hanging over us the threat of really heavy rain on Friday. Up to 25mm is being indicated by plenty of forecasts we look at.
"To give ourselves the best chance of staging a race meeting here on Saturday the thought of putting on three extra chases was discussed. It was agreed that we provisionally got the process going and some entries in and we can take a view further down the line which course of action we take.
"We will take into account current ground conditions and the way the forecast is shaping up 24 hours down the line. It is going to amount to an inspection at 3pm to see which way we go."
31 March 2015Mac magic earns Southwell shock
Royale seal of approval for McCoy
Consort possible for Craven
Fry lines up double Fairyhouse raid
Gatsby seeking Tattersalls gold
Merry King to miss Grand National
Moore has Dundalk ride for O'Brien
Vautour still in Fairyhouse picture
Panther plans open before Gold run
Appleby outlines Charming gameplan
Reserves added to Irish National
Punchestown an option for Bolster
Euro could be saved for Ascot
Tullius to go the distance
Bass angling for Rainbow gold
Dreaper an Amigos ally
Maguire ruled out of National
Sirius camp ponder rise in trip
Solar powered up for Classic charge
Guest treads cautiously with Chrome
30 March 2015Noseda sorry for Sloane reaction
Botti aims high with Naadirr
Flemenstar pleases on comeback
Nicholls trims National team
Bolger rates Lucida highly
Angel in the Hunt for Cup honours
Mullins weighs up Aintree options
Hannon readies Classic team
McCoy rules out Punchestown
O'Brien big guns enjoy away day
Hannon aims high with Windshear
McCoy thrills on Ascot farewell
Huge shock in Park Express
Moore to step up Ballydoyle rides
Jacob ripe for Pineau ride
Varian suffers Kingston 'blow'
Aintree on God's radar
29 March 2015Hero makes his mark for O'Meara
Kristale limbers up for York return
Ferof in hunt for Aintree riches
Telescope back in focus
Clouds given National clearance
Chrome given Royal summons
Flemenstar unplaced on return
Dolniya excels in Sheema Classic
Solow gallops to Turf glory
Gabrial just divine in Lincoln
Naadirr strikes to take Trophy
Sole switches on late power
Tullius has to pull out the stops
Romsdal up and running
Panther pounces for Gold
28 March 2015Prince Bishop rules the World
Prince Bishop rules the World
Raven swoops for De Sousa
Hanagan strikes first blow
Stack harbours Lincoln doubts
Odeliz gears up for Park
Mshawish given green light for Turf
Margarson keeps faith in Guest
Havlin has high hopes with Hopkins
Togo lands another for Pakidis
Longsdon and Fehily rule with Law
Coleman picks up ride on Druids
Power out to end Meydan hoodoo
Jack firmly in Trophy hunt
McCoy honoured with Celebration
O'Brien set on Flat resumption
'Rock star' Chrome seeks World fame