Sandoval reported the injury to manager John Farrell on Wednesday. The club said it has also outlined a conditioning program for him while he's on the DL.
Farrell added that the possibility of a breather would be of benefit to him, especially considering all the scrutiny he's been under since showing up to spring training well out of shape.
"It's been a real tough start. He's been an easy target," Farrell said. "First and foremost, we've got to get him right physically to get past the shoulder issue. But I still firmly believe that Panda is going to be a contributor to this team.
"We're going to need him to be, because there's a darn good player in there."
Sandoval, who is making $17.6 million this year as part of a five-year, $95 million deal, has been relegated to a bench role with the emergence of Travis Shaw at third base. In just seven plate appearances off the bench, Sandoval doesn't have a hit while striking out four times.
As a counter-move, the Red Sox recalled infielder Josh Rutledge from Triple-A Pawtucket.