Tidal Bay has been ruled out of Saturday's Argento Chase at Cheltenham after failing to recover from the setback he suffered earlier this week.
The enigmatic 12-year-old was found to be slightly lame after work on Thursday morning, but after diagnosing the problem as pus in a foot, champion trainer Paul Nicholls described his chances of running as "50-50" on Friday morning.
In the absence of the sidelined Bobs Worth, last month's Lexus Chase hero was set to go off favourite for today's recognised Cheltenham Gold Cup trial, but he will not be lining up at Prestbury Park.
Confirming the news on his Twitter account, Nicholls said: "Tidal Bay a non runner today."
Nicholls later confirmed the Hennessy Gold Cup at Leopardstown on February 9 as a possible alternative for Tidal Bay.
He told Channel 4 Racing's The Morning Line: "It's a shame as it's the perfect race for him (today), but with horses, it's never that easy.
"He worked on Thursday morning and pulled up a little bit sore. He's a lot better this morning according to Clifford (Baker, head lad) but not fit enough to run.
"He's in the Irish Hennessy and if he came together quickly in the next few days we could look at that.
"Other than that, we'll aim for Cheltenham and Aintree with him."
Outsider Calgary Bay is also a non-runner in the Argento Chase, taken out by trainer Mick Channon due to the ground.