Davy Russell missed the ride aboard Sir Des Champs in the Betfred Cheltenham Gold Cup today after suffering a punctured lung.
The rider took a crashing fall from Un Beau Matin at the final flight in Wednesday's Coral Cup but was fit enough to take up his first two mounts on yesterday's card.
However, after finishing unplaced on both Argocat in the Jewson Novices' Chase and Stonemaster in the Pertemps Final, Russell was ruled out for the rest of the meeting.
Michael O'Leary, owner of Gigginstown House Stud, confirmed that Russell had a punctured lung.
"He has a punctured lung which he's had to have drained," said O'Leary.
"He's been stood down for today and tomorrow, he might need a small operation.
"It's quite serious and he can't travel home. His health is my biggest concern."