New Zealand equestrian Andrew Nicholson has decided to withdraw from this week's Badminton Horse Trials in England.
Nicholson, who has been selected for seven Olympics, feels he is personally not at the fitness level required to be competitive at the prestigious event.
He was due to ride Nereo, the horse he won individual bronze and team medals with at the 2010 World Equestrian Games. He also came third on Nereo at Badminton in 2013.
Nicholson said he was recovering from a serious neck injury sustained at the Festival of British Eventing at Gatcombe Park last August, which left him requiring surgery.
"I have reluctantly decided to withdraw Nereo from Badminton - through no fault of his own. I have doubts over my own fitness and ability to do him full justice at this point.
"I successfully rode four horses in the advanced at Withington on Sunday, all of whom won prizes, but was aware I felt fatigued by the end of the seven-minute cross-country course. It would therefore not be sensible to attempt an 11.5-minute course at Badminton.
"I have every confidence my strength and fitness will continue to improve and, with the full support of Nereo's owner Libby Sellar, we now plan to target Nereo towards significant events such as those in the exciting new Event Rider Masters series."
Nereo is a 16-year-old gelding bred in Spain by Ramon Beca.
He won the French CCI4 at Pau in 2012, a couple of months after leading New Zealand to team bronze at the London Olympics, where he and Andrew finished fourth individually.