Arbitrators James Oldham, Margaret Brogan and Howard Edelman made the decision Tuesday, a day after hearing arguments.
Ross hit .290 with 24 homers and 90 RBIs last season, when he made $2.3 million.
Players lead owners 2-1 in cases decided thus far, with Milwaukee outfielder Corey Hart winning $4.8 million. Tampa Bay outfielder B.J. Upton lost and will get $3 million.