World No. 2 Phil Mickelson has suspended his PGA Tour schedule after his wife was diagnosed with breast cancer.

The 38-year-old was due to play at the Byron Nelson Championship starting on Thursday and defend his title at Colonial next week.

But he has withdrawn to be with his wife Amy, 37 at their home in rancho Santa Fe, Ca, she is likely to face "major surgery, possibly within the next two weeks", according to the PGA Tour website.

The Mickelsons have been married since 1996 and have three children (Amanda, Sophia and Evan).

Mickelson is a two-time Masters champion and winner of the 2005 US PGA Championship.

Tiger Woods and a number of other people in the golfing community offered words of sympathy and support on hearing the news.