The No. 2 golfer in the world has suspended his tour schedule to be by his wife’s side as she battles breast cancer. 

Phil Mickelson’s wife, Amy, is expected to undergo major surgery within two weeks as a start to her cancer treatment. She has already endured a battery of tests, with more to come. Mickelson suspended his PGA Tour schedule indefinitely, and withdrew from this week’s HP Byron Nelson Championship, as well as next week’s Crowne Plaza Invitational tournament in Fort Worth, TX, in which he is the defending champion, reports the Fort Worth Star-Telegram.

Mickelson has already won twice this year, has three other top-ten finishes and is a favorite for the U.S. Open at Bethpage, NY, where he finished second to Tiger Woods in 2002, according to the PGATour.com. The San Diego native has 36 PGA Tour wins under his belt, and has earned more than $52 million in his 17-year professional career.

The Phil and Amy Mickelson Charitable Foundation has been involved in Hurricane Katrina relief, the Start Smart program that provides needy kids with clothes and school supplies and the Mickelson ExxonMobil Teachers Academy, which gives teachers innovative ideas and tools to help motivate students. The Mickelsons married in 1996, live in Rancho Santa Fe, CA, and have three children: Evan Samuel, age 6, Sophia Isabel, 7, and Amanda Brynn, 9. Amy is a former Phoenix Suns cheerleader.