Anderson elected free agency Wednesday.
Atlanta outrighted Anderson to Triple-A Gwinnett on Monday.
Atlanta reinstated Anderson (illness) from the 10-day injured list Wednesday.
Anderson (illness) was sent to Triple-A Gwinnett on Friday to begin a rehab assignment.
Atlanta placed Anderson on the 10-day injured list Tuesday, retroactive to June 22, with a bacterial infection.
Anderson agreed to a major-league contract with Atlanta and will be on the active roster for Tuesday's game in Boston.
Anderson signed a minor-league contract with the Mariners on Thursday, Ryan Divish of The Seattle Times reports.
Anderson went 1-for-2 with a two-run home run in the Mariners' Cactus League loss to the White Sox on Thursday.
Anderson signed a minor-league contract with the Mariners on Friday that includes an invite to big-league camp, Ryan Divish of The Seattle Times reports.
Anderson was released by the Brewers on Monday, Adam McCalvy of MLB.com reports.