The Twins called up right-hander John Curtiss on Monday from Triple-A Rochester. Curtiss takes the spot of fellow right-hander Tyler Duffey, who was optioned to Rochester on Sunday.
The 25-year-old Curtiss has compiled a 2.89 ERA over five relief appearances at Triple-A this season, striking out 17 batters and walking just two over 9 1/3 innings. Curtiss came out of the Twins' bullpen for nine games as a rookie last season and allowed eight earned runs over 8 2/3 innings.
Duffey, 27, was optioned after early struggles in which he allowed nine runs (eight of them earned) and four home runs over 5 1/3 innings of relief.