Andy Murray will miss the ATP World Tour Finals in London as he continues his rehabilitation from a back injury that saw him require surgery last month.
The world number three had an operation to repair a damaged disc in September and was hoping to make his return to competitive action at the 02 Arena in the season-ending showpiece.
However, following advice from his doctor, Murray will now concentrate on regaining full fitness for the Australian Open in January.
"I'm really disappointed not to be playing in London this year, I love playing in front of my home crowd, it's a great atmosphere," Murray wrote on his official website.
"All the players look forward to competing in London and I'll be doing my best to qualify again for the tournament next year."
The Wimbledon champion could yet be in action before the end of the year having committed to playing an exhibition tournament in Barbados as the end of November, while he is also scheduled to play in Abu Dhabi in December.
Murray's absence from the London event is a major blow, with tournament director Andre Silva admitting that his presence will be missed.
"It's unfortunate that Andy will be unable to play in this year's tournament," he said. "He's had a historic year on the Tour and of course he'll be missed. We wish him all the best as he continues his recovery from surgery, and we hope to see him back stronger than ever for the 2014 season."
While Murray will be absent, Rafael Nadal, Novak Djokovic and David Ferrer have already qualified for the eight-player tournament which begins on 4 November, with the remaining five places up for grabs in the next four weeks.