Chavez had a 3.54 ERA in 11 relief appearances during the second half. He is coming off a year with career highs in strikeouts (136) and innings (146) and a career-low ERA (3.45).
Chavez is likely to serve as a middle reliever in 2015, the role he has filled for much of his career.
The A's now have eight players that remain eligible for arbitration: Fernando Abad, Ryan Cook, Sam Fuld, Craig Gentry, Brett Lawrie, Jarrod Parker, Josh Reddick and Eric Sogard.
Jamal Collier is a reporter for MLB.com. Follow him on Twitter at @jamalcollier. This story was not subject to the approval of Major League Baseball or its clubs.