Sandoval joined his teammates for Wednesday night's game at Tampa Bay. He took pregame grounders at third, and made throws to first and second base.
"I feel a lot better," said Sandoval, who has been working out six days a week at the Red Sox spring training complex in Fort Myersa. "It's not back to normal, but feeling a lot better. I'm happy to be back here with my teammates. Happy to start doing work."
He has not been cleared to start hitting. Sandoval is expected to be ready for spring training next year.
The 30-year-old Sandoval played three games in his second season with Boston. He was the 2012 World Series MVP with San Francisco.