Phil Mickelson told Golf World's Tim Rosaforte that he will return to the PGA Tour at the St. Jude Classic, following this week's the Memorial Tournament. 

From the Rosaforte piece:

According to sources, Mickelson is basing his schedule on Amy's latest tests and an anticipated surgical date of late June or early July. Beyond a return to Bethpage, where Mickelson finished second in '02, the schedule is day-to-day and will be based on Amy's surgery, treatment and recovery. In other words, the British Open is still up in the air.

The Mickelsons received encouraging news last week that doctors believe they discovered Amy's cancer early, and were uplifted by the "Pink Out" on Saturday at the Crowne Plaza Invitational, where Phil was unable to defend.

Mickelson will be returning to the Tour in the same event that will see John Daly return to the PGA Tour after a six month suspension.