The catcher was acquired from the Brewers last July and batted .212 with six home runs and 19 RBIs in 27 games with the A's. Before that, Kottaras hit .209 with three homers and 12 RBIs for the Brewers, on his way to what would be a career-best .351 on-base percentage on the year.
The Canada native has a career .220/.320/.412 line from his five years with the Red Sox (2008-09), Brewers (2010-12) and A's (2012).
Kottaras was one of four arbitration-eligible players on the A's roster. The remaining three are reliever Jerry Blevins, first baseman Brandon Moss and outfielder Seth Smith.
Gary Cotton is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.