Trainer Paul Nicholls and jockey Ruby Walsh will be reunited when Tidal Bay tackles the Hennessy Gold Cup at Leopardstown.

Walsh became available after his intended mount, the Willie Mullins-trained Rubi Ball, was withdrawn from Sunday's Grade One feature due to injury.

With Boston Bob, owned like Tidal Bay by Graham Wylie, also taken out Mullins was left without a runner and Walsh was suddenly hot property.

It was his former boss Nicholls, who until this season had shared Walsh's services with Mullins, who was first to snap him up for the veteran Tidal Bay.

The 13-year-old ran a blinder in the Welsh Grand National to show he had lost none of his ability and on his only previous visit to Leopardstown he won the Lexus Chase.

"We've decided to go to Ireland with Tidal," Nicholls said.

"It's a small field, good prize money, he's one from one at the track and he'll get his ground.

"Of course Ruby being available also helps, so it has worked out for us."

Tidal Bay is topweight for the Grand National at Aintree and is around 25-1 with most bookmakers.