The Tigers have acquired pitcher Collin hander Ryan Perry.
Balester began his major league career as a starter, but has come out of the bullpen for the last two seasons. In 40 appearances for the Nationals during the 2010-11 seasons, the right-hander posted a 3.81 earned run average and 62 strikeouts in 56 2/3 innings. He also walked 25 and had a 1-5 record.
The 25-year-old has appeared in 62 major league games (22 starts) over four seasons, all with the Nationals. He has also spent time at the Triple-A level.
Perry, 24, split last season between the majors and Triple-A Toledo. He posted a 5.35 ERA in 36 relief appearances for the Tigers, with 24 strikeouts and 21 walks in 37 innings.
In 149 major league games over three seasons with Detroit, all out of the bullpen, Perry owns a 4.07 ERA.