Danoli put up a typically brave performance to hold off Boro Eight in the valuable Aintree Hurdle three days ago, but the true extent of his courage became clear only when he was revealed to have suffered an injury to his off-fore leg during the race, possibly at the penultimate flight.
"It was a complicated fracture to the bottom of his cannon-bone, in the fetlock joint," Riggs said. "This type of fracture can be fairly straightforward or it can be completely devastating. This one is midway."
The first difficult moment after an operation such as Danoli's is when the anaesthetic wears off and the patient stands up. Danoli did so successfully yesterday afternoon, and the plaster-cast protecting his leg was removed shortly afterwards to be replaced by a bandage, but his progress over the next few days will still be crucial to any long-term hopes of a return to the track.
A significant fear is that osteo-arthritis - damage to what Riggs calls the "Teflon coat" which eases movement between the bones - may set in. This coat does not regenerate itself quickly, so any damage would be aggravated by inevitable everyday movements in the joint.
If all goes well, Riggs anticipates "several months in his box and then a very gradual return to training. We wouldn't expect to see him racing for about a year."
Danoli's talent and courage have won him many admirers in Britain, but in his native Ireland his celebrity has been unmatched since the time of Dawn Run almost a decade ago. It is not just his admirable record, which shows 11 victories from 15 outings.
The key factor in Danoli's popularity is his humble background: bought for £7,000 and trained, with just a handful of stablemates, by Tom Foley, who was unknown to all but the most fervent Irish racegoers until Danoli's talent announced itself. If his career is cut short at the age of seven, it will be a dreadful blow to jump racing on both sides of the Irish Sea.
The long-term prognosis for Danoli may not be clear for several weeks or months. But for owners with colts and fillies entered for the Classics, the depth, or otherwise, of their ability must be discovered rather more swiftly, a process which for some will begin with the Easter Stakes and the Masaka Stakes, the first recognised Guineas trials, at Kempton this Saturday.
As far as colts are concerned, of course, all speculation and enthusiasm may prove to have been a waste of energy as soon as Celtic Swing steps on to a track. In the meantime, though, it will be interesting if the likes of Alami, who looked an outstanding prospect until beaten by Sri Pekan in the Champagne Stakes at Doncaster, Blomberg, an easy maiden winner at the same course, Munwar, Missel and Stiletto Blade take their place in the Easter Stakes.
In the Masaka Stakes, for fillies, the contenders may include Cask (John Gosden), Mamlakah (Tom Jones), Spout (Roger Charlton) and Richard Hannon's With The Fairies, who beat Eltish and Juyush in a maiden at Newmarket last June but has not raced since.
A third race at Kempton may hold Classic significance. The declarations for the 10-furlong conditions event include Flemensfirth and Presenting, two of John Gosden's well-regarded Derby entries. Istidaad (Alec Stewart) and Korambi (Clive Brittain), also in the hat for Epsom, are other possible runners.