Bartlett sprained his left ankle Sunday at Cleveland after replacing left fielder Josh Willingham, who was hit by a pitch on the left wrist. Willingham was out of the lineup for Minnesota's home opener against Oakland, and right fielder Oswaldo Arcia was sidelined for the third straight game because of a sore right wrist.
Herrmann hit .204 in 57 games last season for the Twins.
The Twins made another transaction on Monday, acquiring infielder Eduardo Nunez from the New York Yankees for left-handed pitcher Miguel Sulbaran. Nunez, who played in 270 games for the Yankees over the last four seasons, was added to the 40-man roster and assigned to Triple-A Rochester. The 26-year-old hit .260 in 304 at-bats for the Yankees in 2013.
Sulbaran was acquired last summer from the Los Angeles Dodgers in exchange for catcher Drew Butera. Sulbaran finished last season in Class A.