The 10-year-old won the Kerry National at Listowel a couple of years ago and although winless since, he has been running well in defeat of late in conditions softer than ideal.
“All going well Northern Alliance will be there and as long as the ground doesn’t go to soft, he’ll take his chance,” said Martin.
“He’s in good form and we probably shouldn’t have run him on his last couple of runs. He’s finished second and third but the ground in Ireland has been too heavy for him.
“We’ve given him a break and he seems fresh and well. He just wants proper decent ground.”
Northern Alliance is a best-priced 50-1 to claim Aintree glory in April 9.
Oscar Time will be bidding to give owner Robert and his jockey son Sam Waley-Cohen a big-race double following the Cheltenham Gold Cup triumph of Long Run earlier this month.
Trained in Ireland by Martin Lynch, the 10-year-old was last seen finishing third behind Grand National ante-post favourite The Midnight Club in Fairyhouse’s Bobbyjo Chase.
“The Grand National has been the only aim this season and he’s 100% after his last run,” said Lynch.
“I was very pleased with that, it was his first start over fences since the Irish National last year, so we were delighted with it.
“You don’t know until you run them over four and a half miles but he seemed to get the three-mile, five in the Irish National very well.
“He has early pace too and I would hope that he would get the trip, but you just don’t know.
“Any ground will do, that doesn’t bother him.”
Donald McCain is similarly delighted with his National hope Ballabriggs, a winner of two novice hurdles this season before finishing second in a chase at Kelso.
“He worked on Wednesday and we were thrilled with him. He’s in great shape,” said the trainer.
“He needs another two pieces of work, which he’ll have, and that should leave him spot-on.”