With injuries mounting in the starting rotation, the A's turned to a familiar face.

Oakland reacquired right-handed pitcher Aaron Brooks, sending cash to the Milwaukee Brewers. The A's first acquired Brooks alongside injured ace Sean Manaea in a 2015 trade that sent utility man to the Kansas City Royals. 

The 25-year-old finished an 11-game stint in green and gold that year with a 6.71 ERA and 1.59 WHIP. On Feb. 25, 2016, the A's traded Brooks to the Chicago Cubs for Chris Coghlan.

Brooks was traded to Milwaukee last August, but never pitched in a big-league game for either NL Central club. In 99 1/3 innings with Triple-A Colorado Springs this year, Brooks posted a 3.35 ERA and 1.29 WHIP, alongside 2.64 strikeouts per walk ratio. 

In order to make space for Brooks on the 40-man roster, the A's designated Danny Coulombe for assignment. Coulombe made one appearance with the A's after getting recalled from Triple-A Nashville on Sept. 1, allowing one hit on two pitches that same day as the A's used a record-setting nine pitchers in an 8-7 loss to the Seattle Mariners.