Ted Walsh admits it could be late next week before he knows who will ride his John Smith's Grand National hope Seabass.

The nine-year-old has won his last seven starts all told and bids to give his trainer a second National success after Papillon struck in the hands of his son, Ruby, in 2000.

The leading jockey, who also guided Hedgehunter to Aintree glory in 2005, has a tough call to make this year in deciding whether to ride Seabass or one of champion trainer Willie Mullins' team.

It looked odds-on he would ride Mullins-trained ante-post favourite Prince De Beauchene until he was ruled out of the race at the weekend due to injury, but Walsh believes it was not a foregone conclusion which horse his son would have ridden, even if Prince De Beauchene had lined up.

If Walsh jnr does decide to ride for Mullins, or there is an outside chance he could ride Paul Nicholls' Neptune Collonges, his sister Katie is waiting in the wings having guided him to two victories already this season.

"Everything is okay with him at the minute anyway and he's on course for Aintree," said Walsh.

"He'll be taken out of the Irish National later this week as Liverpool is definitely the plan and I'm happy with the horse at this stage.

"We'll have to wait and see who rides him. I'm waiting to see what Ruby wants to do and we'll go from there.

"I don't know why everyone assumed he would be riding the horse that was favourite (Prince De Beauchene), he might have wanted to ride Willie's other horse that won the Thyestes Chase (On His Own).

"He has plenty of options and I won't be doing anything until he lets me know which way he wants to go.

"I'd say it will be Wednesday or Thursday next week before he makes his final decision and I've no problem with that."

Frank Berry expects Sunnyhillboy to line up on Saturday week.

The Cheltenham Festival winner has proved easy to back in recent days.

Last month's Kim Muir winner is a best-priced 16-1 for the world's most famous steeplechase with the industry bookmakers, but was available at double those odds on the betting exchanges.

A decision on whether his Cheltenham Gold Cup-winning stablemate Synchronised will run is expected to be made by this weekend.

Berry, racing manager to owner JP McManus, said: "As far as I know Sunnyhillboy is in good form and on target to run at Aintree.

"Jonjo (O'Neill) is very happy with him, as he is with Synchronised, who seems to have come out of the Gold Cup well.

"He might have another bit of work and we'll make a final decision on him by the weekend."

Meanwhile, Gordon Elliott believes the early stages of the National will be crucial for Chicago Grey.

Well-backed in recent days, the 2011 Cheltenham Festival winner has been prepared with one race in mind all season.

But the nine-year-old has got detached before early on in his races, and Elliott is worried that he could get too far behind too early.

"He schooled last week, schooled very well and stays well, he won the four-miler at Cheltenham last year," said Elliott.

"He's done everything we've wanted him to do this year, Paul Carberry is going to ride him.

"If he can get into a nice rhythm in the first half of the race I think he'll run a massive race. The first four or five fences are going to be very important, if he can get into a rhythm and get jumping."

Paul Nicholls believes Tidal Bay could be a lively contender among his entries for the Bet365 Gold Cup at Sandown on April 28.

The champion trainer has won the final big prize of the jumps season once before, with Ad Hoc in 2003.

But before Sandown is the small matter of the Grand National and both the trainer's Cheltenham Festival winners, Champion Hurdle hero Rock On Ruby and the mercurial Big Buck's, are in contention for a start in Liverpool.

"It's still a long way off but I've got 25-30 possibles for the meeting," Nicholls said.

"We need to sit down and think about it at the end of the week.

"We're looking at Big Buck's running, and Rock On Ruby and Zarkandar will run in the Aintree Hurdle."