Murphy, seeking his first victory in the big race from 12 attempts, felt he could not desert the more fancied runner especially after winning the Eider Chase at Newcastle.
“I think it was the safest decision. He’s proved that he stays and that he jumps safely, two things you need to do in the National,” he said.
“Vodka Bleu is an old favourite of mine and a lovely old horse. We’ve had some great days. He’s been round here while Comply hasn’t, (but) I couldn’t get off the second or third favourite for a 33-1 shot.
“The Eider probably didn’t probably ride the greatest race to me, but the physical act of carrying 12st over four miles and going away from the others at the end is what I was impressed with.
“He raced well against Cloudy Lane at Haydock and he’s been kept fresh for this. This is race you have to be trained for, not a last-minute decision,” he told Racing UK.
Robert Thornton has also been out of luck in 11 tries and believes the first few fences will be crucial for the Alan King-trained D’Argent.
He added: “I schooled D’Argent on Monday. He’s kind of got his own way of doing things jumping-wise, but I’m not going to change that.
“He’s in good form so as long as I get him into a rhythm early he’ll certainly give me a good ride.”
King hopes D’Argent takes to the unique fences as the 11-year-old bids to become the first grey to win the world’s greatest steeplechase since Nicolaus Silver in 1961.
“I have no idea whether D’Argent will take to the fences on Saturday – I think we’ll know our fate early on in the race,” he said.
Bewleys Berry fell at Becher’s on the second circuit last year, but Howard Johnson’s charge has got round the famous course twice when finishing runner-up in the last two renewals of the Becher Chase.
Owner Graham Wylie said: “He was pulled up last time and there were two reasons for it. Firstly it was very heavy ground and he doesn’t go on that.
“Howard (Johnson) wanted to get him out before Aintree and the only other option was at Doncaster, where it was firm, and we didn’t want to risk him on that either.
“The other thing is that he doesn’t seem to run very well anywhere apart from Aintree. They say horses for courses, and he’s one of them.
“He’s only ever won for me on his first time as a novice chaser at Wetherby. Everywhere else he’s been disappointing, but he just seems to light up at Aintree and let’s hope he does so on Saturday.”
Connections of Dun Doire and Philson Run breathed a sigh of relief as their horses made the cut in a maximum 40-strong field.
The defection of Cornish Rebel brought the Irish-trained Dun Doire into the line-up, while Ollie Magern’s expected absence through lameness saw last year’s fourth, Philson Run, given another chance.
Dun Doire’s trainer Tony Martin said: “It would have been disappointing for everyone concerned if he hadn’t got in.
“I’m very happy with him and he’s as good as we can have him. If he gets luck in running hopefully he’ll put up a good show.”
Nick Williams, responsible for Philson Run, was another happy man.
“We had trained the horse the whole year for one race and we’d have had egg on our face if he hadn’t got into the race,” Williams told At The Races.
“Last year was a delight. Three out I felt he would be in the first three, but he slightly emptied. In a perfect world we would like to see more rain. It takes some of the speed out of the race if there is some cut.”
By contrast, Cornish Rebel’s trainer Lisa Williamson tried to hide her disappointment.
“Unfortunately he’s just got a problem with one of his feet,” she said.
“We’ll just give him a few days and try to get him sound again.”
There are four horses on standby, should any in the line-up be declared a non-runner by 9.30am on Friday.
The reserves, in order, are: Ardaghey, Joes Edge, In The High Grass and Ossmoses.
Ante-post favourite Cloudy Lane features as the Trevor Hemmings-owned eight-year-old bids to give trainer Donald McCain a fairytale success by continuing the family tradition.
His father, Ginger, saddled four National winners – triple hero Red Rum (1973, 1974, 1977) and Amberleigh House four years ago.
Cloudy Lane has already been a massive gamble - backed at all rates from 25-1 down to his current price.