Walters was acquired by the Royals on Wednesday, Jeffrey Flanagan of MLB.com reports.
Walters came to the Royals from the Kansas City T-Bones of the Independent League. The 27-year-old spent some time with the Reds' Triple-A affiliate early in the season, but he was let go after slashing .174/.208/.239 in 48 plate appearances. The switch-hitter hasn't been assigned to a minor-league affiliate yet.