The right-hander was called up Saturday and will return to St. Paul after firing two scoreless frames against Pittsburgh. Across two stints in the majors this year, Klein has given up two earned runs with 2:4 K:BB in three appearances (4.1 innings).

Klein has conceded two earned runs in just 2.1 innings with the Twins this season, but since being optioned to Triple-A on May 7, he's posted a 3.65 ERA and 0.89 WHIP with a 16:5 K:BB across 12.1 innings. Now back with the big club, he'll presumably work in a multi-inning role out of the bullpen, replacing Simeon Woods Richardson, who was DFA'd in a corresponding move.