Kaminska was assigned to Triple-A Pawtucket upon being acquired, the Red Sox announced. The 24-year-old went 9-4 with one save and a 4.19 ERA in 40 games split between the Marlins and Pirates organizations last season.
The 6-foot-4, 180-pound righty has pitched in only two games at the Triple-A level and spent most of the year with Miami's Double-A affiliate in Jacksonville, Fla., where he went 6-3 with a 5.11 ERA and 42 strikeouts in 49 1/3 innings. He walked just 1.2 batters per nine innings last season, not far below his career 1.8-per-nine-innings mark.
Kaminska also played in the Arizona Fall League this year, going 3-1 with a 1.61 ERA, 21 strikeouts and only four walks in 28 innings over six starts.
Kaminska was the Marlins' 25th-round pick in the 2007 First-Year Player Draft and spent five years in Miami's organization before getting dealt to Pittsburgh at this year's July 31 non-waiver Trade Deadline. He owns a career 30-28 record with a 4.22 ERA and 400 strikeouts in 135 appearances, including 66 starts.