Dufner has a sore neck because of a degenerative arthritic condition. He also blames himself for not staying in better shape.
The 37-year-old Dufner had an epidural early last week, then tied for 66th at Firestone. He feels like the only way to get healthy is to take six to eight weeks off, but can't afford to do that with the Ryder Cup approaching.
Dufner is eighth in the points and figures he needs to earn one of the nine automatic spots to be on the team. Given his health, he wouldn't expect to be one of the three picks by U.S. captain Tom Watson.
If Dufner qualifies, he may sit out the FedEx Cup playoffs to ensure he's healthy.