Ross, 34, is best known for his contributions to the San Francisco Giants' 2010 World Series run. Ross batted .288 with three home runs and seven RBIs in 33 games for the Giants following a mid-season trade. He then posted a 1.076 OPS in the playoffs and won the NLCS MVP thanks to a .350/.435/.950 slash line and three home runs in six games.
Ross batted .252 for the Diamondbacks in 2014, with a .628 OPS and two home runs in 219 plate appearances. He signed a three-year, $26 million contract in Arizona before the 2013 season.
The veteran will provide outfield depth for an Oakland team that has had its share of injuries. The Athletics placed outfielders Coco Crisp and Josh Reddick on the disabled list before Opening Day.
- Alex Putterman