SAN DIEGO - SIX weeks after Phil Mickelson announced his wife had breast cancer, his mother was diagnosed with the disease and is to have surgery later this week.

The San Diego Union-Tribune reported on its website that Mary Mickelson discovered she had breast cancer last week. She is to have surgery on Friday at the MD Anderson Cancer Center, the same hospital where Mickelson's wife, Amy, had surgery last Wednesday.

Mickelson's sister, Tina, told the newspaper she wanted to make her mother's condition known so she could receive the same outpouring of support and prayers that meant so much to Amy Mickelson.

Mickelson has not spoken publicly since the US Open, where he was a runner-up for a record fifth time.

His parents live in the same San Diego house where they raised their three children.

Mickelson said at Bethpage Black that it was 'highly unlikely' he would play the British Open, and said his schedule the rest of the year depended on his wife's battle with cancer. -- AP