It was a hard call for the champion jockey to reject his other JP McManus-owned option, the Jonjo O’Neill-trained Sunnyhillboy, who was beaten by the narrowest margin in National history 12 months ago by Neptune Collonges.
However, with Sunnyhillboy carrying 10lb more this year, McCoy has gone for the potential improver, who marked himself out as a potential National horse when winning the Paddy Power Handicap Chase at Leopardstown over Christmas.
“He’s won his last two races while Sunnyhillboy has the experience of being round here and is trained by Jonjo O’Neill, which is the biggest plus there is in staying chases,” said the 17-times champion jockey.
“Colbert Station has less weight, he is a bit inexperienced but is a bit more unexposed, too.
“The Paddy Power Chase is not anywhere near as good a race as the Grand National, but it’s very competitive in terms of hustle and bustle. With 30 runners it is like a mini-Grand National.
“For a horse that has little jumping experience he has had the experience of a tough competitive chase like that.
“Hopefully he’s got a good chance. If Colbert Station doesn’t win I hope Sunnyhillboy does. He was second last year, he has lots of positives and it was a tough decision.
“It was pretty much my decision in the end. It’s always difficult getting off one of Jonjo’s horses in these long-distance chases.
“The only thing is that Ted Walsh has a pretty good record in the National as well. That was a plus point.”
Walsh also runs Seabass, third last year and once again partnered by his daughter, Katie.
Sunnyhillboy will again be ridden by Richie McLernon.
Imperial Commander is at the head of the weights after the good ground at Aintree persuaded his connections to let him take his chance after he missed the Gold Cup with a minor infection.
His trainer Nigel Twiston-Davies also has two more strings to his bow in Major Malarkey, ridden by Tom Scudamore, and Viking Blond (Adam Wedge), who is the final horse of the 40 declared runners.
The ante-post favourite is Willie Mullins’ On His Own, ridden by Ruby Walsh. Mullins also runs Quel Esprit and Quiscover Fontaine.
Champion British trainer Paul Nicholls, who claimed his first National last season in such thrilling circumstances, has Join Together (Daryl Jacob), What A Friend (Sam Thomas) and Harry The Viking (Ryan Mahon).
What A Friend and Harry The Viking are part-owned by Manchester United manager Alex Ferguson.
Donald McCain runs 2011 winner Ballabriggs, Weird Al and Across The Bay, while Nicky Henderson, still searching for his first win in the race, is represented by Roberto Goldback.
Chicago Grey and Tarquinius run for another former successful trainer in Gordon Elliott.
Elliott was set to have a third runner in Backstage, but he scoped badly yesterday morning.
Cappa Bleu, fourth last year, is aiming to maintain Evan Williams’ great recent record of having had a placed runner for the last four years.
Oscar Time, second two years ago, is back again and will be ridden by Sam Waley-Cohen.
Mortimers Cross and Pentiffic are the two reserves.
There had been some doubt over whether Paul Carberry would be fit to take the mount on Chicago Grey after a fall at Fairyhouse on Tuesday, but the veteran Irish pilot declared himself fit.
“There seems to have have been a big improvement so I’ll be fine,” said Carberry. “I think he’s got a cracking chance – Gordon’s horses are running ever so well at the moment.”