The 34-year-old second baseman, who has not played a major league game since May 2011 because of post-concussion symptoms, will be added to Baltimore's 25- and 40-man rosters sometime Tuesday so long as symptoms do not surface from his final rehab game at Triple-A Norfolk on Sunday.
Up to Sunday, Roberts had played 13 minor league rehab games over the last two weeks, hitting .263/.370/.474 and experiencing no concussive symptoms.
Roberts suffered his initial concussion late in 2010 by hitting himself on the helmet with his bat in frustration after a strikeout. Back with the team for the beginning of the next season, Roberts a second concussion on May 16, 2011, when he hit the back of his head sliding into second base at Fenway Park. Post-concussive symptoms from the two injuries have kept Roberts away from baseball activities for over a year.
A two-time All-Star, Roberts has a career .281/.353/.416 line and averaged 42 doubles a season from 2004-2010.