For details see above link
From ESPN’s fantasy draft analysis: “Signed to compete for a reserve/pinch-hitting role by the Red Sox, Overbay no longer packs the power punch that he possessed even three short years ago. His isolated power has been beneath .150 in back-to-back years, and since he’s generally a pull-power lefty, he’s not the ideal fit for Fenway Park’s spacious right-center field. Even if Overbay makes the team, he shouldn’t be more than AL-only roster-filler.”