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 Bobs Worth, as revealed by trainer Nicky Henderson on Thursday, has been withdrawn from the final field due a bad scope earlier in the week.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.
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