Jackson signed a minor-league deal with the Brewers that includes an invite to major-league spring training.
Jackson last pitched in a major-league organization with the Padres in 2015, mostly appearing at the Triple-A level. The 31-year-old spent the last three seasons with the Hiroshima Carp in the Japan Central League, posting a 2.10 ERA, 1.13 WHIP and 9.8 K/9 across 175 appearances.