Dave Dombrowski, who was named president of baseball operations of the Red Sox in August, pulled off the boldest move of his brief tenure in Boston on Friday, shipping four prospects to the San Diego Padres for closer Craig Kimbrel.

In exchange for Kimbrel, a four-time All-Star, the Red Sox parted ways with one of their most promising minor-leaguers in outfielder Manuel Margot, as well as shortstop Javier Guerra, infielder Carlos Asuaje, and left-hander Logan Allen.

"When we look at Craig, we look at him as a premium closer, and there are various names out there, but [Kimbrel is] one of the best in the game of baseball," Dombrowski told MLB.com's Ian Browne. "I think the key for us is we had identified some guys that stood above the rest, as far as the ability to close. We thought the ability to get one of those guys was extremely important."

Tasked with bolstering a roster that fizzled in 2015 following a series of high-profile offseason signings, Dowbrowski hinted earlier this week that he could unload serious prospect capital this winter, telling reporters that he was likely to "do something that is painful one way or the other."

But while Boston's farm system isn't as impressive as it was a few hours ago, their bullpen will now inspire fear throughout the American League - something it failed to do in 2015. Last season, the Red Sox received an appalling -1.4 wins above replacement from their bullpen - the worst mark in the majors - en route to a last-place finish in the AL East.

ERA (AL rank) WHIP K% BB% HR/9 4.24 (13th) 1.40 (14th) 20% (13th) 8.8% (T-9th) 1.37 (15th)

Kimbrel, meanwhile, endured an uncharacteristically ugly start to the season, his first in San Diego, but still finished the year with a 2.58 ERA and 1.05 WHIP in 61 appearances. Though his peripherals dipped a bit this summer, Kimbrel still leads all relievers in WAR (12.9), saves (225), and strikeouts (563) since his 2010 debut. Kimbrel is also one of just two relievers in history to log at least 200 appearances with ERA+ above 190 and a WHIP of 1.00 or less; the other is Mariano Rivera.

Year ERA FIP WHIP SV K/9 2010 0.44 1.53 1.21 1 17.4 2011 2.10 1.52 1.04 46 14.8 2012 1.01 0.78 0.65 42 16.7 2013 1.21 1.93 0.88 50 13.2 2014 1.61 1.83 0.91 47 13.9 2015 2.58 2.68 1.05 39 13.2

Not surprisingly, Kimbrel - owed $24 million over the next two years with $13-million team option for 2018 - will assume closing duties in Boston, with Koji Uehara sliding into a setup role after logging 72 saves over the previous three seasons.

"I'm excited," Kimbrel said. "With the history and the fans in Boston, the atmosphere is always awesome every time I've been there. You can feel the history and everything behind it there. To be able to play in front of those fans is going to be a lot of fun."

With his team unlikely to compete for a playoff spot in 2016, conversely, Padres general manager A.J. Preller opted to swap his best (and most expensive) reliever to further improve his farm system. Kimbrel, in fact, is the second Padres reliever to be traded in the last 36 hours, as veteran right-hander Joaquin Benoit was dealt to the Seattle Mariners on Thursday for minor-league right-hander Enyel De Los Santos, and infielder Nelson Ward.

Margot, the crown jewel of Preller's haul, was hailed as the game's 24th-best prospect by Baseball America back in July, shortly after the 20-year-old was promoted to Double-A Portland. Despite facing pitchers more than four years his senior on average, Margot hit .271/.326/.419 with 28 extra-base hits through his first 64 games in Double-A, striking out in just 12.8 percent of his plate appearances while playing plus defense in center field.

Guerra, also 20, is lauded more for his defense at shortstop than his offensive potential, but the Panama native still smashed 15 homers with a .778 OPS with Low-A Greenville in 2014. Though Asuaje, the other infielder acquired by San Diego, struggled at Double-A this season, Preller said the 24-year-old has a chance to win the Padres' vacant shortstop job in spring training.

Allen, meanwhile, made eight starts after being taken in the eighth round of last year's draft, enjoying tremendous results in his first season as a professional. The 18-year-old fashioned a 1.11 ERA with a 26:1 strikeout-to-walk ratio across 24 1/3 innings, mostly in the Rookie-level Gulf Coast League.

"You don't ever like to give up young talent," Dombrowski added. "We think they're very talented individuals."