The Padres provided the update Sunday.
Blanks tore his labrum while swinging a bat. He missed time in spring training with the injury, but started the season with San Diego and played in four games before going on the disabled list on April 14.
The 25-year-old Blanks had Tommy John surgery on his right elbow that ended his 2010 season. Blanks has a career .219 average with 20 homers over parts of four seasons with San Diego.