Reserve outfielder Darin Mastroianni was placed on the 15-day disabled list with a strained left oblique muscle before the game Wednesday against Kansas City. Twins relievers logged 11 2/3 innings over the last two games against the Royals.
Boshers signed with the Twins as a minor league free agent before the season. He has a 1.42 ERA in 19 innings with five walks and 21 strikeouts for Rochester. Boshers has 25 career major league appearances, all in 2013 with the Los Angeles Angels.
To make room for Boshers on the 40-man roster, closer Glen Perkins (strained left shoulder) was transferred to the 60-day disabled list.