The Boston Red Sox acquired Joel Hanrahan from the Pittsburgh Pirates in a six-player swap. Jon Heyman tweeted that the Pirates will receive four players and the Red Sox will receive two. Jerry Sands and Stolmy Pimentel are known to be headed to Pittsburgh.

Hanrahan, 31, was 5-2 with a 2.72 ERA and 36 saves for the Pirates last season. For his career he is 22-17 with a 3.74 ERA and 96 saves over six seasons spent with the Washington Nationals and the Pirates. Hanrahan has been an All-Star the past two seasons for the Pirates and has saved 76 games over that span.

Hanrahan is eligible for arbitration this year and is scheduled to become a free agent after the season. Boston's bullpen struggled in 2012 when Andrew Bailey went down with an injury. Alfredo Aceves saved 25 games, but was 2-10 with a 5.36 ERA. They have also added Koji Uehara to the bullpen this off-season.

Sands, 25, was acquired from the Dodgers on August 25th in the blockbuster that sent Adrian Gonzalez, Carl Crawford and Josh Beckett to Los Angeles. He has hit 119 home runs in is minor league career. Sands has 251 major league plate appearances and has hit .244/.325/.376 with four home runs in that limited time.

Pimentel, 22, was 6-7 with a 4.59 ERA over 22 starts for Double-A Portland. He is 39-41 with a 4.37 ERA over six minor league seasons.

The Pirates are expected to use Jason Grilli as their closer in 2013.