SAN DIEGO (AP) -- Phil Mickelson withdrew from the Farmers Insurance Open on Friday night because of muscle pain in his back.
Mickelson shot a 1-over 73 on the South Course at Torrey Pines in the second round, leaving him eight strokes behind leader Jordan Spieth. Mickelson said after the round that he feared getting into bad habits by altering his swing to keep his back from hurting. This is hometown tournament and he said he wanted to keep playing.
His management company released a statement late Friday evening that Mickelson had decided to withdraw. Mickelson said he would talk to doctors to figure out the best course of action.
Mickelson is to defend his title next week in the Phoenix Open.
''I love this tournament and I want to play here. I love playing in San Diego and this is a place where I grew up playing, so I really want to play,'' Mickelson said after his round. ''And part of me also says that I'm getting in bad habits. And if I hit it in this rough here, I've really got an issue because I've got to swing awfully hard to get it out and it jars it. So I'm a little torn right now on the best plan of action.''
He was eight shots behind Jordan Spieth.
Mickelson doesn't have a history of back problems. It began to bother him last week in Abu Dhabi, where he was a runner-up.
But even after treatment overnight, and some improvement, the pain returned and he said he was altering his swing to avoid his back hurting. He averaged 265 yards off the tee, which is 23 yards below last year's average for driving distance.
''The first tournament of the year and I'm always excited to start the year, but I also want to be smart because I'm getting into some bad habits so I've got to sort of weigh where I'm at,'' Mickelson said earlier Friday. ''I would love to go out and at least give it a try early on and see if I can get a hot hand and maybe get something going, but I also want to be smart about this.''
Mickelson plays a busy West Coast schedule. After Phoenix, he is scheduled to play at the AT&T Pebble Beach National Pro-Am the following week. Mickelson is not planning to play at Riviera or Match Play because his children have spring break at two schools.
''I have the entire year. I've got majors coming up. I've got other tournaments coming up and I don't want to get in bad habits,'' Mickelson said. ''My game is pretty sharp getting ready to start the year and I could tell I'm making terrible swings out there relative to the way I've been swinging.''