MINNEAPOLIS -- Twins right-hander Brian Bass left Thursday's game in the fifth inning with a lower back strain.
Bass pitched to just three batters before exiting the game. He had just finished issuing an intentional walk to Eric Hinske when he motioned to the dugout for help.
Twins manager Ron Gardenhire and trainer Rick McWane came out to the mound, and after a brief discussion, Bass headed to the bench. Right-hander Matt Guerrier was then called in from the bullpen.
Bass had entered the game in the fifth inning after starter Boof Bonser had loaded the bases with no outs. Bass threw a total of 14 pitches in his outing.
He is listed as day-to-day.
Kelly Thesier is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.