SAN FRANCISCO -- Phil Mickelson doesn't know how he injured his back, but he does know that his ailment isn't going to affect him during the Presidents Cup.
"I was getting ready to go practice and it just tightened up," he said Wednesday at Harding Park. I wasn't doing anything. It just tightened, and it's not that it's an issue."
Mickelson received treatment from back specialist Tom Boers, a physical therapist at the Hugston Clinic in Columbus, Ga. Boers' client list of golfers also includes Davis Love III, Fred Couples and Greg Norman.
"I just wanted to be precautious because I am looking forward to this week and there's a lot of golf left and I didn't want to go in not taking it. It's a little muscular deal. It's not a big deal. It feels great now."
Mickelson also said it's doubtful that his wife, Amy, would attend the Presidents Cup. She had surgery for breast cancer in July and is still undergoing treatment.
-- Thomas Bonk