The former world number one will not play in next week’s Wyndham Championship and cannot qualify for the FedEx Cup play-offs – missing out for just the second time since the post-season began in 2007 – leaving just the Ryder Cup to aim for.

Woods has made only seven starts all season, the second fewest in his career, missing three months and the Masters and US Open after undergoing back surgery on March 31.

He has recorded no top-10 finishes for the first time in his career and earned just $108,275, and while he is not exactly short of money, it should be noted that he has earned more than that in 176 individual PGA Tour events in his career.

But as grim as the statistics are, perhaps what is most telling was the 14-time major winner’s response when asked when he will play again.

“I don’t know,” the 38-year-old said. Asked what he would say if US captain Tom Watson calls and asks about a wild card for the Ryder Cup, the response was the same: “I don’t know, he hasn’t called.”

Whether Watson calls at all remains to be seen, with Woods far from the only player causing the 64-year-old some sleepless nights ahead of next month’s contest at Gleneagles.

World number six Matt Kuchar, who has already secured his place on the team, pulled out before the start of the US PGA due to back spasms, while defending champion Jason Dufner lasted just 10 holes before being forced to withdraw with a neck injury.

Dufner started the week eighth in the Ryder Cup standings with the top nine on Sunday evening qualifying automatically, but dropped to ninth after Zach Johnson made the cut at Valhalla and said he was not sure when he would be able to play again.

Dustin Johnson, who was the only American player unbeaten at Medinah in 2012, was fifth in the standings before declaring himself unavailable as he takes a leave of absence to deal with “personal challenges”.

As former European captain Colin Montgomerie said this week, it would be a massive gamble for Watson to pick players who are not fully fit, with the prospect of them needing to play five matches in three days at Gleneagles.

Woods will at least try to get fit as soon as possible, admitting he was too stubborn to withdraw before his second round at Valhalla despite reinjuring himself on the range.

“I need to get stronger, I need to get my glutes strong again, my abs and my core back to where I used to have them,” he said. “They are just not quite there yet.

“I couldn’t make a backswing. Coming through (the ball) is fine, I can’t get the club back. (The injury) throws everything off. I can’t get anywhere near the positions that I’m accustomed to getting to. I can’t do it. I’ve got to rely on timing, hands, and hopefully I can time it just right.

“It’s hard because you want the bigger muscles controlling the golf swing. I have got to rely on my hands to do it. The face is rotating so fast through impact because I’m just not able to get my arms and the body in the correct spot.”

That does not sound like what Watson had in mind when he said he would pick Woods if he was healthy and playing well. The one consolation is that the only time the United States have won the Ryder Cup in the 21st century – here at Valhalla in 2008 – Woods was also ruled out through injury.

Paul Azinger, who was widely praised for his captaincy in a five-point win in 2008, said he would not pick Woods for this year's team.

“I don’t think I would. I don’t see how you can take an injured player who is not playing well,” Azinger told the Golf Channel.

“And also Tiger has not necessarily been the formula for success either. I just don’t see how you can pick him at this point.

“I am guessing he will call Tom and beg out of this and say I am not ready, make Tom’s decision easier.”