St Nicholas Abbey is to undergo surgery on a fractured pastern which has ended his career and threatened his life.

The six-time Group One winner suffered the injury during a routine gallop at Aidan O'Brien's Ballydoyle stable on Tuesday morning as he continued his preparations for Saturday's King George VI And Queen Elizabeth Diamond Stakes at Ascot.

With his racing career now over, owners John Magnier, Michael Tabor and Derrick Smith of Coolmore are hopeful their vets can save him for a stud career.

"St Nicholas Abbey suffered a fractured pastern during a routine piece of work at Ballydoyle this morning," Coolmore tweeted.

"He is currently in a comfortable condition at Fethard Equine Hospital, where he is scheduled for surgery tomorrow morning.

"The operation to stabilise and repair will be long and complicated - we will need a bit of luck, so fingers crossed for St Nicholas Abbey."

A son of Montjeu, St Nicholas Abbey was champion two-year-old in 2009 when he crowned his season with a blistering display in the Racing Post Trophy at Doncaster.

He was a red-hot favourite for the 2000 Guineas the following year, but could only finish sixth behind Makfi, and was not seen again until the following April when he was beaten at the Curragh.

He returned to something like his juvenile form when an easy winner of the Ormonde Stakes at Chester and went on to further Group One glory in the Coronation Cup at Epsom, a race he went on to win twice more.

Arguably his two greatest successes came in his two international victories in the 2011 Breeders' Cup Turf in 2011 and the Dubai Sheema Classic at Meydan earlier this year.