Tidal Bay now has a "50-50" chance of running in Saturday's Argento Chase at Cheltenham depsite his late injury scare.
Champion trainer Paul Nicholls will declare 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 Nicholls 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 on Friday morning.
"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.
"A lot can happen in 24 hours. 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."
