Tidal Bay now has a "50-50" chance of running in Saturday's Argento Chase at Cheltenham.
Paul Nicholls has declared the Lexus Chase winner at the overnight stage but his participation depends on how he responds to treatment. The problem was diagnosed as pus in his foot and his trainer says a lot can happen in 24 hours.
"Tidal Bay has marginally improved and I would now rate his chances of running in tomorrow's Argento Chase at Cheltenham at 50-50," Nicholls told Betfair.
"The problem was pus in his foot and, without getting technical, we are adopting the normal treatments and procedures in these circumstances. I have had plenty of horses with a similar problem in the past, and they have run in the same timeframe.
"It is all about how he responds to the treatment now, but we are heading in the right direction. He will be left in the race at the overnight stage, and we will make a decision in the morning. He will be given an hour on the walker this morning, and again this evening, so we will keep him ticking over. Fingers crossed."
Tidal Bay is one of 12 horses declared for the Argento. Bobs Worth, as revealed by trainer Nicky Henderson on Thursday, has been withdrawn from the final field due a bad scope earlier in the week.
Imperial Commander, the 2010 Gold Cup winner, will be having his first outing for 680 days following a rotten sequence of injuries and setbacks. Nigel Twiston-Davies' 12-year-old will be joined in the line-up by stablemate Little Josh, who won the Grand Sefton at Aintree in December.
Grands Crus, third in the King George VI Chase at Kempton last time, is also engaged for the David Pipe team. Hunt Ball is being campaigned for the Betfred Cheltenham Gold Cup and has been given the green light by his colourful connections.
Weird Al is an interesting contender on his first start since finishing fourth in the Betfair Chase at Haydock, while Cape Tribulation takes his chance for Malcolm Jefferson. Last year's winner Midnight Chase will attempt to atone for being pulled up in the Lexus Chase at Leopardstown over Christmas.
The rejuvenated Wayward Prince has also been declared by owner-trained Hilary Parrott. Calgary Bay, Hey Big Spender and Quartz De Thaix complete the field.
22 July 2014Queen's Estimate tests positive
Moonlight shines at Musselburgh
Taghrooda could go off favourite
Signal pointed at Phoenix
Course specialist in Ascot return
Bary plots Arc route for Spiritjim
Charlton weighs up Kazeem options
Strangeway targets Galway riches
Grade One status for Mares' event
Halford retains Certerach faith
Varian seeking York glory
HRI unveil 2015 plans
Buick on Ascot weather watch
High hopes for Odeliz
Minella to take Plate test
Scudamore banned for course blunder
Toscanini team mull options
Faydhan team in no rush
Fast Kaar given Dewhurst target
Pique Sous confirmed for Galway
Hannon team cool on Nunthorpe bid
Channon excited by Amralah progress
Haggas expects Hanagan to ride Tag
21 July 2014Ebor the Clever choice for Cookie
Deauville mission for Fiesolana
Chicquita in Yorkshire Oaks frame
Magical Moore shines again
Kool result for Hannon
Guest considers Memory options
Euro stays with Botti
Ascot on Moohaarib agenda
Injury blow for Boistron team
Encke set for Glorious return
No hurry for Tiggy target
No rush for East aim
20 July 2014Sous heads Galway Hurdle betting
McCoy savours overtaking Pipe
Bracelet glitters in Irish Oaks
Whittington pounces in Anglesey
Music masters Hackwood rivals
Dazzling Tiggy in Nunthorpe frame
Gutsy Ansgar makes all
India too hot in Curragh opener
Fourth for Kazeem on return
Kosika crushes Newbury rivals
19 July 2014Bracelet glitters in Irish Oaks
It's a day to remember for McCoy
It's a Rasen Gimme for McCoy
Super-sonic display from Tiggy
Bay bounds clear for Summer spoils
Sunshine at last at Rasen
Storms force Market Rasen delay
Lady bids to bow out on a high
Ansgar takes Minstrel chance
Newsletter out to deliver
Cox pair take Super challenge
Kazeem on the comeback trail
Tennant sitting on big Rasen prize
Newland seeks easy Pickens at Rasen
Realtra camp have Sprint concern
Tarfasha team hopeful of home win