World No 2 Phil Mickelson will miss next month's WGC-Accenture Match Play Championship in Arizona to take a family holiday which had to be postponed because of his wife Amy's cancer treatment.

The elite World Golf Championships (WGC) events are just one rung down from the majors but the American lefthander said he would skip this year's edition because his three children would be out of school.

"I love the Match Play and I love Tucson but it was the best week for us to have a family vacation that we had to reschedule because of our procedures," Mickelson said on the eve of Thursday's opening round at the San Diego Open.

"We had a couple of procedures scheduled for this offseason that got postponed. We had to move one into March and this affected some of our family trips."

Mickelson's wife and his mother were diagnosed with breast cancer last year, forcing the three-times major winner to limit his playing schedule for 2009.

"I expect this to kind of happen a little bit throughout this year, maybe missing tournaments I would like to play or normally would play," Mickelson said.

"But later on in the year, I'll probably add a tournament that I hadn't originally planned on playing to kind of offset it."

Mickelson said the long-term outlooks for the two women were favorable.

"Amy and my mom are doing great and things have gone very well," he said. "But even in the best-case scenario, dealing with cancer is never easy and so it's not easy for them."

Mickelson said he planned to play in the next three PGA Tour events before skipping the Feb 17-21 WGC-Accenture Match Play Championship in Tucson.

"Then I'll play the following week in Phoenix," the 39-year-old said. "I'll take the next week off, when we again have some stuff treatment-wise and I should be able to play Doral, the World Golf Championship."

Mickelson will be defending his title at Doral, his one-shot victory in last year's WGC-CA Championship giving him his first WGC crown.

Mickelson heads the field at the San Diego Open where world No 1 and six-time winner Tiger Woods is a notable absentee after taking an indefinite break from the game.