Maier was designated for assignment on July 4, and it was announced on Saturday that he cleared waivers and was assigned to Triple-A Omaha.
The outfielder is the longest tenured member of the Royals' organization. The former first-round Draft pick in 2003 made his big league debut as part of a five-game stint in 2006. From 2008-12, he played in 355 games with the Royals, hitting .249 during that time.
A logjam in the outfield over the last two seasons, though, has limited Maier's playing time. He played in just 45 games a season ago, and saw action in just 32 games this season for the Royals.
Manager Ned Yost said that heading back to Omaha would allow Maier an opportunity to play.
"He gets to go play and get sharp again," Yost said. "He's a viable guy, but he just needs to play. He sat here for two years, and he just needs to go back out and play. He'll go down there and do well. We'll see him again."