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 Bobs Worth, as revealed by trainer Nicky Henderson on Thursday, has been withdrawn from the final field due a bad scope earlier in the week.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.
27 August 2015Tested passes with flying colours
Tested passes with flying colours
Baker tempted by Woodbine for Bill
Memory poised for Haydock chance
Treve clash possible for Queen
Iffranesia shoots for Bullet glory
Hills to make French Connection
Burke plots Reflection Ayr raid
Fascinating entry in Winter Hill
Forgotten horse up for Irish Leger
Thumbs-up at Ffos Las
Bear a necessity in Celebration
Pallasator in Cup mix at Doncaster
Lynam sprinters Flying first class
Emotionless bound for Doncaster
Ground key to Rectifier run
Second inspection at Ffos Las
Whip ban for Mulrennan
Tryster in line for September clash
All systems go for Pendleton
Palmer firming up Covert mission
Safety first for Appleby
Stevens to end training career
Cumani content with Postponed work
Storm stars in Leger list
Irish Champion excites Glen camp
26 August 2015Spear Celebration 'highly unlikely'
Williams ponders Bullet plans
Barron belief in Bing
Salvo seeks solace at lower grade
'Laid-back' Erupt ready for action
Rain pain at Ffos Las
Take Cover back in Flying form
Bookmakers agree possible merger
Big-race targets on Marjurie agenda
Oppenheimer relaxed on Horn options
Bright future forecast for Wizard
Sea charts path to Treve clash
Epsom option for Berkshire
Ranger sights set on Bullet
Irish Leger option for Brave
Point plans up in the air
Ward retains Finnegan faith
25 August 2015Deauville date for Sumbal
Simenon team mull future plans
Surface switch for Lingfield heats
Brighton gets the go-ahead
Brighton gets the go-ahead
Three and easy for Godolphin
Pendleton poised for Ripon first
Euro chasing Breeders' dream
Acapulco back for more next year
Panther set for racecourse gallop
Maarek fired up for Beverley Bullet
Moyglare beckons for Now Or Never
Letters future excites O'Callaghan
Curragh aim for Goldream
Kodi in Celebration frame
24 August 2015Brighton takes precautions
Kachy camp consider Middle Park
Guiliani in Irish Champion hat
Thornton return delayed
Glory sights set on 2016
Vison sights switch to Ayr raid
Cowell seeking Streak revival
Dream team wait on ratings verdict
Easton in line for Flying Childers
Haydock option for Moviesta
Odeliz stuns Romanet rivals
Herald The Dawn stars for Bolger
O'Brien admits Gleneagles 'worry'
Found much too good at the Curragh
Ebor hero Litigant to leap in class
Ground key to Muthmir plans
Lumiere grazed after York eclipse
Zawraq out for the season
Haydock a must for Weld star