Phil Mickelson's expects to be fit for his title defence at the Waste Management Phoenix Open following his withdrawal from the Farmers Insurance Open because of a back injury.

Mickelson made the halfway cut at Torrey Pines but was then forced to pull out of the event before the start of Saturday's third round.

The 43-year-old, who finished joint second in Abu Dhabi on the European Tour the previous week, then flew to Georgia for a consultation with back specialist Tom Boers.

Although not at 100 per cent, Mickelson said on Wednesday he expects to play.

He said on "I had a good practice session, though I didn't go full speed for much of it. I feel fine. I expect to play and play well."

Mickelson, who opted out of Wednesday's pre-tournament pro-am, won by four shots last year, leading from start to finish after a stunning opening round of 60 that could so easily have been a magical 59.

He said earlier: "If it was any other tournament I'd skip it, but I'm defending, it's my second hometown and I love the event. I'll have a light practice session and if it goes well I may try to play.

"I'm itching to play, but I have to look at the big picture. I have a number of tournaments I want to play and play well this year, including the majors, so I have to be realistic about how I feel in the short term."