Jackson signed a minor-league deal with the Reds on Friday, John Fay of The Cincinnati Enquirer reports.
The 32-year-old signed with the Chiba Lotte Mariners in Japan during December, but he'll return to affiliated ball with the Reds and report to the alternate training site. Jackson spent 2019 with the Brewers and had a 4.45 ERA, 1.32 WHIP and 47:18 K:BB over 30.1 innings.