Manager John Farrell told reporters Ramirez is day-to-day.
Ramirez was injured while chasing a line drive off the bat of James Loney into the corner. The ball landed in his glove but bounced out after he hit the wall. The umpires ruled no catch and the Red Sox challenged, but the call was upheld and Ramirez was charged with an error.
Ramirez retrieved the ball and then fell to one knee, clutching his left shoulder. He walked off the field slowly and was replaced by Allen Craig.
Ramirez signed with the Red Sox as a free agent this winter and is adjusting to playing the outfield. Before arriving in Boston, he had never played the outfield as a professional.
Ramirez is batting .283 this season with 10 home runs, the second most in the majors.
- Dan Gartland