The Scot needed to make the final of the Paribas Masters in Paris in order to topple Novak Djokovic as the world’s best and was due to face Milos Raonic on Saturday afternoon.
But his job was done for him as the Canadian withdrew from their clash with injury, giving the Wimbledon champion a walkover.
Speaking in the French capital, Raonic said his leg injury could now affect his participation in the season-ending Tour finals in London.
“Yesterday I started feeling something in my leg, this morning I had trouble getting out of bed,” he said.
“I did an MRI and they found I have a grade one tear in my right quad and I am not able to compete.”
The news caps arguably the greatest year of Murray’s career.
Chasing down Djokovic - considered virtually untouchable at the start of 2016 - the 29-year-old took Wimbledon glory and retained his Olympic gold, lifting seven trophies in total.
He will now face John Isner in a 12th final of the year and will do so knowing he is rated as the world’s best player.