Cherry Hills - Phil Mickelson withdrew from the BMW Championship before the start of the third round at Cherry Hills Country Club on Saturday, saying he wanted to rest for this month's Ryder Cup.
By pulling out of the penultimate FedExCup playoff event, world No 10 Mickelson ensured he would miss next week's finale in Atlanta for the first time in his career.
The American left-hander, a 42-time winner on the PGA Tour, had qualified for the elite Tour Championship every year since the lucrative four-event playoffs were launched in 2007.
"My primary goal is to rest and prepare for the Ryder Cup," Mickelson, 44, said in a statement released by his management company.
"Without a chance to contend at the Tour Championship, the most important thing for me now is to prepare for the Ryder Cup."
The United States will take on holders Europe at the 40th Ryder Cup from September 26-28 at Gleneagles in Scotland.
Mickelson had faced an uphill task to qualify for the September 11-14 Tour Championship after opening with rounds of level-par 70 and 76 at Cherry Hills to languish 14 shots off the lead,
Only the leading 30 players on the FedExCup points list after the BMW Championship advance to Atlanta and Mickelson, who began this week in 56th place, was projected to slip to 64th based on his start at Cherry Hills.
Mickelson is one of only three players who have qualified for the Tour Championship every year since 2007, along with fellow Americans Steve Stricker and Hunter Mahan.
Stricker was eliminated from this year's playoffs after pulling out of the series opener, the August 21-24 Barclays tournament, due to a hip injury
Mahan won the Barclays title to vault to the top of the FedExCup standings, though he had slipped to third place coming into this week.