According to Mark Sheldon:

The contract of OF Derrick Robinson was purchased from Triple-A Louisville to replace Ludwick on the roster.

Robinson batted .300 in 22 spring games after being signed in the off-season as a Minor League free agent. He batted .258 in 116 games last season for the Royals’ Triple-A affiliate in Omaha. A switch hitter, he has never played in the big leagues.