"I've lost some strength in my left arm and I had a hard time hanging onto the club," Stricker said while driving home to Wisconsin. "It just kept getting worse."
Stricker, who had rounds of 76-70 at Cog Hill, said he consulted a neurosurgeon Friday morning who recommended a couple of days of rest. He said he would get a cortisone shot Monday that should allow him to play in the Tour Championship.
He attributed the weakness in his arm to a disk problem in his neck that he first noticed in December while bow hunting.
"I found it when I went to pull back my bow to shoot a doe," he said. "My left arm caved down and I hit my head with the bow. I thought that was unusual. I had never had that problem before. That was a wakeup call that something was wrong."
Stricker said he had an MRI that revealed a disk problem, which explained the loss of strength in his left arm. He has been spending more time on fitness and exercise to alleviate the pain. Even so, Stricker said if he could pull down 40 pounds using his right arm, he could pull down only 20 pounds with his left arm.
He still managed to have another strong year, winning at the Memorial and the John Deere Classic. He is No. 2 in the Presidents Cup standings and No. 8 in the FedEx Cup.
Stricker tied for 24th at The Barclays and tied for 42nd in the Deutsche Bank Championship, two playoff events where he typically plays well.
"The last month or so, I've noticed that it's gotten a little worse," he said. "I put a lot of time in the last three days, and I don't think that's helped. But I'm going to see this doctor on Monday, and hopefully I'll be ready to go."
The Tour Championship is his last tournament for a month. Stricker had said he might play Disney as a tune-up for the Presidents Cup in Australia, which is Nov. 17-20 at Royal Melbourne. He combined to win all four team matches with Tiger Woods, and is expected to pair with Woods again.