Interim manager Torey Lovullo made the announcement before the Red Sox faced the Tampa Bay Rays at Fenway Park on Thursday.
Ramirez has been sidelined since Aug. 27. He was placed on the disabled list Sept. 5.
During his time on the DL, the former shortstop was transitioning from being a left fielder to playing first base. He took grounders a number of times.
Signed as a free agent to an $88 million, four-year deal during the offseason, Ramirez hit .249 with 19 homers and 53 RBIs.