Captain Conan fractured his pelvis when pulling up in Wednesday's Queen Mother Champion Chase at Cheltenham.
The seven-year-old was sent off the 7-2 second-favourite behind Sire De Grugy but was pulled up lame at halfway.
Trainer Nicky Henderson is relieved to report the problem does not appear to be too serious.
"Captain Conan had an excuse, he has a fracture to his pelvis," he told Racing UK.
"It's not displaced, though, which is a good thing.
"Usually, if you give them box rest for a month that does the trick."