By Jeff Louderback

The trade for right-handed closer Joel Hanrahan is completed, the Red Sox announced on Wednesday.

Boston acquired the 31-year-old Hanrahan and minor league middle infielder Brock Holt for outfielder/first baseman Jerry Sands, right-handed reliever Mark Melancon, infielder Ivan De Jesus Jr. and minor league pitcher Stolmy Pimentel.

Hanrahan, who is projected to receive $6.9 million through arbitration in 2013 and can become a free agent next offseason, was 5-2 with a 2.72 ERA and a 1.27 WHIP while earning 36 saves for the Pirates in 2012. He struck out 67 in 59.2 innings, allowing just 40 hits, but his 5.4 walks per nine innings ratio is a concern. In 2011, Hanrahan walked only 2.1 batters per nine innings while logging a 1.83 ERA, a 1.05 WHIP and 40 saves.

The 24-year-old Holt was a ninth round pick of the Pirates in 2009 out of Rice University and is a promising second baseman/shortstop. In four minor league seasons, he has a .317 average and a .808 OPS, including an impressive 2012 campaign when he batted .322 in 432 plate appearances at Double-A Altoona, .432 (yes, .432) in 106 plate appearances at Triple-A Indianapolis and .292 in 72 plate appearances in his Major League debut with Pittsburgh.

Holt will provide Major League ready middle infield depth at Triple-A Pawtucket, replacing De Jesus, who is also a versatile infielder.

Hanrahan’s addition bolsters the Red Sox bullpen, and the trade also cleared tw0 spots on the 40-man roster. Chances are, the club will fill one with Mike Napoli, whose contract is still being worked out after Red Sox officials were reportedly alarmed about the results from the catcher/first baseman’s physical.

Projections range on Sands. SoxProspects.com says that he “projects as a bench player at the Major League level, capable of filling in during stretches.” CBSSPorts.com’s Jon Heyman Tweeted that Sands is “a terrific athlete with power.” Heyman added that Sands has a high ceiling and compared him to a Matt Holliday type.

Likely, the SoxProspects.com description is more accurate. When they acquired him from the Los Angeles Dodgers in last summer’s blockbuster deal, the Red Sox envisioned Sands as a first baseman and left fielder off the bench in 2013.

Once a highly regarded prospect, the 22-year-old Pimentel has struggled the last two seasons. He logged a 9.12 ERA in 15 starts at Double-A Portland to open the 2011 campaign and was demoted to advanced Single-A Salem, where he had a 4.53 ERA in 11 games (10 starts) while attempting to regain his confidence. In 2012, Pimentel was 6-7 with a 4.59 ERA in 22 starts at Portland.

Hanrahan will likely compete with Bailey for the closer’s role in what is shaping up to be a strong Red Sox bullpen. Though the 28-year-old Bailey struggled to a 7.04 ERA in 19 games after returning from thumb surgery that he underwent at the end of spring training, he is a proven closer when healthy, as his three seasons in Oakland indicate.

Uehara has closing experience, though he is best suited as a set-up man at this stage of his career. Junichi Tazawa, who delivered an impressive performance in 2012, will serve as a a key late-inning reliever. Franklin Morales and Alfredo Aceves give the Red Sox two arms capable of filling a set-up role, a long relief job and a spot starter.

The Red Sox hope that reuniting with John Farrell and returning to a full-time relief role will resurrect Daniel Bard, who suffered through an atrocious 2012 season. Left-handers Craig Breslow and Andrew Miller, and right-handers Clayton Mortensen and Alex Wilson, will also be competing for spots on the Opening Day roster.