The Twins activated righthanded reliever Tim Stauffer from his rehab assignment at AAA Rochester and returned Doug Bernier to the minor league club. Stauffer had been on the disabled list because of a right intercostal strain, missing 19 games with Minnesota. He made foiur rehab appearances at Rochester, posting a 5.40 ERA in four games.

Bernier, a utility infielder, was 1-for-5 (.200) in four games, but had a pair of RBI during his time with the Twins.

Stauffer's addition comes after the Twins used eight pitchers in Wednesday's 4-3, 13-inning victory at Pittsburgh. The Twins have a three-game series at the Chicago White Sox starting Friday night.

Stauffer opened the season on the Twins roster and had an 8.38 ERA in eight appearances, allowing 16 hits in 9.2 innings. He was having trouble breaking 90 mph with his fastball, and the club is hoping the strained muscle was the reason.