Walsh, who recorded a double on the opening day at Cheltenham, suffered a fall from Al Boum Photo at the second-last in the RSA Chase on day two, and was immediately brought to Gloucester Royal Hospital.
It was just his fourth day back in action, having broken his leg in a fall from Let’s Dance at Punchestown in November, and it was the injury from which he had just returned which was aggravated.
In the immediate aftermath Walsh feared he had damaged the leg at its weakest point, and yesterday’s visit to his specialist, Diarmuid Moloney, confirmed his suspicions.
“Having spoken with my specialist, I know it would be too much of a rush to make it back in time for Aintree, which is in the middle of next month, but I am aiming to be back in time for Punchestown,” said Walsh.
“As suspected last week, I got confirmation that it is a similar fracture, at the inside of the old one. The original fracture was oblique, and it has beaked, which effectively means it has opened.
“How long exactly it will take to heal I don’t know, but I’m optimistic that Punchestown, at the end of next month, is a target I can realistically aim for.
“It has been a frustrating season and last week’s fall was just another setback. As jockeys we all understand the risks involved, and this, unfortunately, is part of what we have to deal with.”
Before suffering the fall, Walsh’s victories aboard Footpad, in the Arkle Chase, and Benie Des Dieux in the Mares’ Hurdle, had brought his Festival tally to 58, which is more than 20 more than the next most successful rider at the Cheltenham Festival.
Meanwhile Ruby’s sister, Katie Walsh, is looking forward to having another crack at Randox Health Grand National glory aboard outsider Baie Des Iles.
It is six years since Walsh steered Seabass to finish third in the Aintree spectacular for her father, Ted, which remains the highest-placed finish for any female jockey in the history of the race.
Trained by the leading amateur rider’s husband, Ross O’Sullivan, grey mare Baie Des Iles was last seen finishing third when bidding for back-to-back victories in a Grand National trial at Punchestown in February.
She is a best-priced 66-1 to claim a historic victory on Merseyside.
Walsh said: “Ross was delighted with her run in Punchestown. She had a lot of weight in very heavy ground and ran a cracker.
“It was a lovely run and I wasn’t over-hard on her. She comes here off the back of that. It’s still a month away, so a lot can happen between here and then, but fingers crossed.”
While many trainers will be giving their National hopes a sighter over custom-built Aintree fences between now and April 14, Baie Des Iles, who has been handed a weight of 10st 7lb, is likely to tackle the obstacles for the first time during the race itself.
“She ran in France and they’ve a lot of different obstacles over there. Touch-wood, she seems to be a good, safe jumper, so I don’t think there’d be any reason why she should (school over National fences),” Walsh added.
“A lot of her form is on soft to heavy ground, but, for me, I don’t feel she wants it as soft as her form suggests.
“I think the track will definitely suit and the trip will without doubt suit.
“So much can go right and so much can go wrong, but hopefully with a bit of luck she’ll be here in good order.”