Tiger Woods has ruled himself out of contention for next month's Ryder Cup because of injury.
The 38-year-old American, who failed to qualify automatically for the Gleneagles event, has been suffering from a persistent back problem.
Woods had surgery in March and has been told not to play by doctors.
"While I greatly appreciate Tom [Watson] thinking about me for a possible captain's pick, I must take myself out of consideration," he said.
|Iain Carter, BBC golf correspondent|
|"Tiger Woods has done the American Ryder Cup team a big favour by withdrawing. Skipper Tom Watson has been spared a difficult decision, one that could easily have undermined the US effort to regain the trophy. The uncertainty over whether Woods would receive a wildcard was already starting to have a corrosive effect on the captain's authority." Read more|
"I've been told by my doctors and trainer that my back muscles need to be rehabilitated and healed. They've advised me not to play or practice now.
"I'm extremely disappointed that I won't be ready for the competition. The US Team and the Ryder Cup mean too much to me not to be able to give it my best."
World number 11 Woods, who has played in seven Ryder Cups but only been on the winning side once, was sidelined for three months following his surgery, but reported no pain when he returned to action in June.
He finished level 69th at the Open in July, his worst showing in that event as a professional, and shot a pair of three-over-par 74s at the US PGA at Valhalla to miss the cut for only the fourth time in a major championship.
Last week's US PGA Championship was the final tournament to count towards qualification for the US Ryder Cup side, and Woods' failure at Valhalla left him 70th in the US Ryder Cup standings, 61 places off a qualifying berth.
Watson will make his three captain's picks on 3 September.
|United States - the nine automatic Ryder Cup qualifiers|
The US captain has endured a bad couple of weeks, with Dustin Johnson announcing he was taking a break from golf, Matt Kuchar pulling out of the US PGA with a back problem and defending champion Jason Dufner withdrawing during his first round at Valhalla with a neck injury.
Europe will go into the tournament in Perthshire, Scotland, which takes place between 23-28 September, as the holders.
Jose Maria Olazabal's team beat the United States 14.5-13.5 at the Medinah Country Club in Illinois in 2012.