Chamberlain, 29, was signed by the club as a minor league free agent on August 16, pitching in eight games for the Storm Chasers, going 1-0 with a 6.43 ERA, with two walks and nine strikeouts in 7.0 innings. The veteran righty opened the year with the Detroit Tigers, posting a 0-2 record and a 4.09 ERA in 30 appearances at the big league level.
Coleman, 28, has pitched for Kansas City in each of the last four seasons after being selected by the Royals in the fifth round of the 2009 June Free Agent Draft. He was 8-2 with a 1.69 ERA (12 ER in 64.0 IP) at Omaha this season, also recording nine saves in 38 appearances. The righty held the opposition to a .212 batting average, while he posted 63 strikeouts in 64.0 innings. Coleman has made 148 big league appearances with the club, going 5-4 with a 3.25 ERA, with a .225 opponents' batting average.
The Royals Major League reserve list remains at 40 players, while there are 35 players on the club's active roster.