Ramirez was first put on the disabled list on May 26. He struggled with lingering symptoms for quite a while before beginning a rehab assignment three weeks ago. Ramirez says he sought the counsel of Twins first baseman Justin Morneau, who has a long history with concussions.
Ramirez hit .184 during 14 games on his rehab assignment. He will give Twins manager Ron Gardenhire a backup center fielder. The Twins have been thin at that position since sending struggling rookie Aaron Hicks down to Triple-A Rochester on Aug. 1.