Bochy first told KNBR radio of Sanchez's surgery, which was an arthroscopic procedure. Sanchez also had surgery on his left knee to repair a torn meniscus in early October.
"He's going to be a little delayed," Bochy told the AP. "It'll be close if he can go Opening Day or not."
Sanchez, 32, was plagued by shoulder and knee injuries last season, which limited him to just 25 games with the Giants after coming to the team via trade on July 9.
Sanchez batted .284 with a home run and seven RBIs in those 25 games after batting .296 with six home runs and 34 RBIs in 86 games with the Pirates.
Even with his injury problems last season, Sanchez was rewarded with a $12 million, two-year contract extension with San Francisco on Oct. 30.
The eight-year veteran is a career .299 hitter with 38 home runs and 300 RBIs in 733 games with the Red Sox, Pirates and Giants.
Rhett Bollinger is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.