Phil Mickelson has suspended playing on the PGA Tour indefinitely after his wife was diagnosed with cancer, officials said Wednesday.

The breast cancer in Amy Mickelson was discovered after an "extensive battery of tests," the golfer's manager T.R. Reinman said in a release.

More tests are scheduled but the treatment process is expected to begin with major surgery, perhaps within the next two weeks, Reinman said.

The couple married in 1996 and have three children aged nine, seven, and six.

Mickelson, 38, is a two-times Masters champion and winner of the 2005 PGA Championship.

The world No 2 was due to play the Byron Nelson Championship in Dallas beginning Thursday and defend his title at the Colonial Invitational in Fort Worth next week.

"Phil made exactly the right decision," Nelson tournament chairman Charley Spradley said. "He has handled this in just the fashion any of us would. ... Our thoughts and prayers are with the extended family, all the Mickelsons and her family."

The situation casts doubt on Mickelson's participation in next month's US Open at Bethpage in New York, where in 2002 the big left-hander finished second to Tiger Woods.

"Elin and I are deeply saddened to hear the news about Amy," Woods was reported as saying on US Tour web site pgatour.com.

"Our thoughts and prayers are with her, Phil, the children and the entire Mickelson family."

PGA Tour Commissioner Tim Finchem said in a statement: "We are saddened by the news of Amy Mickelson's diagnosis, but are hopeful that with the support of Phil and her family and friends, she will come through this difficult time."

The Mickelsons were one of the most highly visible couples on the US PGA Tour as Amy often followed her husband from the galleries at the major tournaments.

The birth of their first child, Amanda, in 1999 drew wide publicity as Amy was poised to give birth as Mickelson was contending against Payne Stewart at the U.S. Open in Pinehurst.

Mickelson carried a pager in his golf bag and said he would leave the championship if his wife went into labour.

He ended up losing by one stroke to Stewart, who holed a 15-foot putt on the last hole on Sunday to win, but Mickelson made it home in time for Amanda's birth the next day.

(Reuters via China Daily May 22, 2009)