Tony McCoy has decided to ride the Ted Walsh-trained Colbert Station in Saturday's Grand National at Aintree.

The champion jockey faced a difficult choice as his other JP McManus-owned option was Jonjo O'Neill's Sunnyhillboy, beaten by the narrowest margin in National history 12 months ago by Neptune Collonges.

"He's won his last two races and has less weight," McCoy told Channel 4 Racing.

"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."

Walsh also runs Seabass, third last year and once again partnered by his daughter, Katie.

The pre-post favourite is Willie Mullins' On His Own, ridden by Ruby Walsh, Ted's son and Katie's brother.

The same trainer and jockey teamed up for National glory with Hedgehunter in 2005.

Champion trainer Paul Nicholls, who claimed his first National last season in 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 Sir Alex Ferguson.

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 has declared himself fit.

Former Australian Pentiffic, now with Venetia Williams, is the first reserve for the world's most famous steeplechase.