I think the day-to-day injuries are the games when a player gets injured, leaves a game, but no long term injury shows up after the game. I think the day-to-day number reflects past injured games, and has no bearing on his use in upcoming games. In your roster status page, Barmes is not listed as injured, and should be able to be played in any game to his full potential.
His day-to-day injury number on the injury page, will probably remain there for the rest of the season, and may go up if he gets hurt during a game, and is forced out of the game, but shows no long term injury in the post game roster.