Trainer Paul Nicholls believes that there is still a chance that Kauto Star will be able to compete in the Cheltenham Gold Cup later this month.
The French-bred racehorse was given a "50-50" chance of appearing in the competition after suffering a fall in schooling last week.
"He's been sound ever since," Nicholls told Sky Sports News."He cantered on Saturday and he's cantered every day since. He's having physio already this morning. He's going to canter as normal today.
"We're hoping we can get him there. There's just a chance that we might not be able to get him there so we thought we'd better let people know. It's very minor, he's just a little stiff.
"We're still hopeful, we've still got a fortnight. He needs to be at his very very best to run in the race. That's what we need to get him at. There's just a chance he might not."
Kauto Star is a two-time winner of the Cheltenham Gold Cup.