Former world number one Tiger Woods has withdrawn from the Omega Dubai Desert Classic before the start of his second round due to a back injury.
Woods insisted he had not suffered a setback despite his comeback continuing in demoralising fashion, the 14-time major winner failing to card a single birdie as he slumped to an opening 77, two shots worse than his previous highest score in the event.
The 41-year-old had said on Wednesday that his latest swing has been designed to "play away from pain" as he returned to action following the injury which required three operations in the space of 19 months.
However, he did not look 100 per cent fit at various points in his round, climbing gingerly out of a greenside bunker on his first hole and notably grimacing as he walked off the tee on the seventh, his 16th.
"No, I wasn't in pain at all," Woods said after the first round at Emirates Golf Club. "I was just trying to hit shots and I wasn't doing a very good job. At the end I finally hit some good ones but the damage had already been done."
Woods had never finished outside the top five in his first five appearances in Dubai, lifting the trophy in 2006 and 2008 and enjoying a scoring average of 68.71.
But his opening 77 had left him with a massive task to avoid a second missed cut in a row after making an early exit from his first PGA Tour event since August 2015 in San Diego last week.
It remains to be seen how serious the setback is, with Woods set to have a week off before competing in the Genesis Open at Riviera and the Honda Classic at PGA National.
However, it is certain to fuel speculation that the greatest player of his generation, who has not won a major championship since 2008, could be close to the end of his stellar career.
Woods' agent Mark Steinberg said the withdrawal was due to a back spasm, but that Woods was pleased it was not the nerve pain which had previously caused the biggest problems.
"He can't get the spasm to calm down," Steinberg told reporters in an interview also broadcast on Sky Sports. "That's where we are. He feels terrible; talked to (playing partners) Matthew (Fitzpatrick) and Danny (Willett) and feels awful.
"He can move around, he just can't make a full rotation on the swing."
Asked if he had experienced similar spasms recently, Steinberg added: "Spasms are a funny thing. I'm certainly no doctor but they come and go. The fact that he feels though it's not the nerve pain, that's very encouraging for him. He's had some spasms before no doubt about it.
"He's got to get the spasm to calm down. He has his trainer here which is good. That's who has been working on him for the past several hours.
"He'll get it to calm down and forget about the long term, the short-term prognosis he thinks hopefully will be strong based on the fact that it's not that nerve pain."
Steinberg said Woods had not been in pain during or after his opening round, but admitted the long flight to Dubai could have been a factor.
"It's one of those where it just happened," he added. "I'm sure there are so many different factors that could play into it. He doesn't have the strongest back in the world right, so it's probably easier to spasm because of the issues he's had.
"But he wanted to be here. He wants to be here and just feels terrible he can't finish it out today."