Headley fractured the tip of his left thumb while sliding into second base during a spring training game, jamming it into the bag while trying to break up a double play.
Headley led the National League in RBI last season with 115. The Gold Glove third baseman hit .286 with a career-best 31 homers over 161 games for the Padres in 2012.
San Diego also placed infielders James Darnell and Logan Forsythe on the 15-day disabled list while promoting 12-year MLB veteran utility infielder Cody Ransom and infielder Jedd Gyorko, drafted by the Padres in the second round of the 2010 MLB June Amateur Draft out of West Virginia.
Celebrity Families of 2014 [PHOTOS]