Brewers place Aaron Wilkerson on 10-day IL
Wilkerson, 29, has made three appearances for the Brewers this season, and pitched 1 2/3 innings for Milwaukee in a loss to the New York Mets on Sunday, striking out two while allowing two hits, two earned runs and two walks.
Hart, 28, has walked four and allowed two hits in 2 1/3 innings for the Brewers this season, and has a 7.36 ERA in eight appearances in Triple-A.
Jackson, 31, last pitched in the majors for the San Diego Padres in 2015, and has allowed four hits with 14 strikeouts in seven games in Triple-A this season.
Wilson, 32, has made 13 appearances for the Brewers this season.
He struggled in his most recent outings, allowing a home run in a loss to the St. Louis Cardinals on April 23 and a home run in a win over the Mets on Saturday.
Wilson has allowed 15 hits and 12 earned runs with 13 strikeouts and nine walks in 11 1/3 innings for Milwaukee this season.