The pair had been due to compete at the five-star show in Geneva this week (8-11 December), hoping to stake their claim on the Rolex Grand Slam of Show Jumping and the €1million bonus on offer.
But the injury, reported to be a relatively minor twist to a leg joint, means Big Star will not be able to jump until January.
As a result, the Olympic champions will also miss the London International Horse Show at Olympia next week (13-19 December). There had been much excitement surrounding the pair’s first competitive reappearance on home soil since winning gold at the Olympic Games in Rio in August.
“He has twisted a joint, it’s nothing terrible but four to six weeks rest from top level competition is the order of the day; and it goes without saying that is what we will do,” said Nick.
“We are all extremely disappointed that he will not be making his presence felt at both these shows but trust everyone understands that his welfare is paramount.
“He is fine to be ridden and exercised gently so we are still aiming to parade him at Olympia. He is such a character, who could possibly deprive him of being in the spotlight once again, especially when it is on home soil at such a special show!”.
The parade of Olympic medallists at Olympia takes place on the evening of Friday 16 December.
Gary and Beverley Widdowson’s 13-year-old Quick Star stallion has jumped at two shows since winning Olympic gold four months ago. He and Nick helped the Great Britain team finish second in the Nations Cup final in Barcelona with a tremendous double clear and gallant jump-off effort. Last month the multi-winning partnership secured two podium places in Toronto, including third in the World Cup qualifier.
Big Star had been lightly jumped in the build-up to the Olympics after a 15-month lay-off with a suspensory injury incurred in the summer of 2014. Nick and the stallion returned to competition at the end of 2015.
The pair made their first tilt at the Rolex Grand Slam in 2013, winning the Aachen grand prix. However, injury ruled Nick and Big Star out of the second leg at Spruce Meadows in September of that year.
Nick has been nominated for BBC Sports Personality of the Year, which takes place on Sunday 18 December in Birmingham and will be broadcast live on the Sunday evening. To vote online, you will need to pre-register here.