Macey has pulled out of Thursday's decathlon

The Commonwealth champion suffered the injury in a final training session and then failed a late fitness test.

The 28-year-old was one of Britain's best medal hopes and had been receiving urgent treatment from team doctors.

Macey said: "If there was any chance I could go out there, take a pain jab, I'd be out there - but there just wasn't any possibility."

Interview: Dean Macey

Macey will now fly home after deciding he is not fit enough to contest the 10-discipline event.

He said: "It's easy to say it now, but I'm in good shape - I considered myself a medal chance.

"I've never gone into a decathlon with 10 events going really well, but nine of my events were superb this month.

I certainly felt like, Roman Sebrle aside I was the best in the field. A gold medal was not out of the question.

"The bottom line is that it was a very difficult decision to make, but one that had to be made."

Macey's career has been plagued by injury and he has not competed since his gold in Melbourne.

He broke down in tears at a media conference on Sunday when he revealed his latest setback.