In addition, San Francisco dealt Matt Joyce to Atlanta for cash. The Giants, under new president of baseball operations Farhan Zaidi, have been searching all offseason for an impact outfielder to balance their lineup amid an abundance of left-handed hitters.
Reed has played in 22 major league games, with Milwaukee in 2015-16 and the Braves last season. He batted .342 with a .453 on-base percentage between Triple-A Gwinnett and Double-A Mississippi in 2018.
On Friday, San Francisco released Cameron Maybin, arrested on suspicion of DUI during spring training. Left-hander Steven Okert was designated for assignment Saturday to clear room on the 40-man roster for Reed, who will join the major league team.
Andreoli, claimed off waivers by San Francisco on Feb. 1, appeared in 26 games between Seattle and Baltimore last season.