Chambers, 29, batted .280 with 18 doubles, two triples and one homer in 88 games with Iowa.
The other Minor League players suspended were Braves pitcher Steve Borkowski and Giants pitcher Alvaro Diaz.
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings. You can follow her on Twitter @CarrieMuskat and listen to her podcast. This story was not subject to the approval of Major League Baseball or its clubs.