SEATTLE -- When the Mets traded for Addison Reed in August 2015, he was a middling former closer with a career 4.20 ERA, recently returned from a Minor League demotion. Over nearly two full seasons with the Mets, Reed transformed into something more, a wipeout late-game artist with a keen command of the strike zone.

Reed became, in other words, a luxury the Mets do not need as they play out the remainder of this season far removed from playoff contention. So the Mets traded him on Monday, flipping Reed to the Red Sox for a trio of hard-throwing right-handed pitchers: Stephen Nogosek, Jamie Callahan and Gerson Bautista, the Red Sox's 18th-, 23rd- and 28th-ranked prospects according to MLB Pipeline. Reed is a free agent after this season.

AJ Ramos, whom the Mets recently acquired from the Marlins, will serve as their ninth-inning stopgap until Jeurys Familia returns from the disabled list, likely at some point late this season. The Mets also received another relief prospect, Drew Smith, in last week's trade of Lucas Duda.

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"We're pleased with how things developed and turned out over the course of the week," Mets general manager Sandy Alderson said. "Net-net, we have I think a high-quality back end of the bullpen type in AJ that will be with us in 2018. The four arms that we added in the other two deals we're very pleased with."

In Nogosek, Callahan, Bautista and Smith, the Mets reacquired some of the pitching depth they lost in a series of Deadline deals the past three seasons, including those for Yoenis Cespedes, Jay Bruce, Kelly Johnson and Juan Uribe.

Nogosek, 22, was a sixth-round Draft pick in 2016. He has posted a 4.08 ERA in relief for Class A Advanced Salem, with six of the eight runs against him coming in a single outing. Overall this season, Nogosek has used his low- to mid-90s fastball, slider and cutter to post a 3.06 ERA with 63 strikeouts in 53 innings. He becomes the Mets' 23rd-ranked prospect.

Callahan, the Red Sox's second-round Draft pick in 2012, is a 22-year-old whom Alderson specifically mentioned as a short-term option for New York's bullpen. A former starter who rates as the Mets' 29th ranked prospect, Callahan has improved since his conversion to relief work, posting a 4.03 ERA in 22 games at Triple-A Pawtucket.

Bautista, also 22, was a high-profile signing out of the Dominican Republic in 2013. Capable of reaching the upper 90s with his fastball, he was pitching to a 5.16 ERA in Salem, with 53 strikeouts in 45 1/3 innings.

"They all for the most part throw mid-90s and up," Alderson said. "We simply didn't have arms in that range over the last couple of years, given some of the trades we made to be competitive in [2015] and '16. So having been able to replenish those arms, I think we're happy about that."

The cost for all that talent was Reed, who blossomed into one of baseball's best end-game relievers after arriving in New York, posting a 2.09 ERA in 145 games. This year, Reed served mainly as the Mets' closer in place of Familia, who is rehabbing from arterial surgery. In that role, Reed saved 19 games in 21 chances with a 2.57 ERA, and 48 strikeouts in 49 innings.

"We think he can come in and be a premium setup guy for us," Red Sox president of baseball operations Dave Dombrowski said."

Trading Reed is not necessarily the last deal the Mets will make this summer. Over the coming days, the club is likely to place much of its roster on waivers, potentially clearing the path for additional deals in August. Among those who could go are infielders Asdrubal Cabrera and Neil Walker, and outfielders Bruce and Curtis Granderson.

The Mets have incentive to make such deals; their promotion of top-rated prospect Amed Rosario creates a roster crunch in the infield, while their outfield has been crowded for much of this season.

"We've gotten players before in August," Alderson said. "It's very possible that some or all of those players will clear waivers. So it's a possibility that things will develop."

Fantasy spin | Fred Zinkie (@FredZinkieMLB)

Reed (2.57 ERA, 1.12 WHIP) should provide helpful ratios for American League-only owners out of a setup role, but he is unlikely to receive the necessary save chances down the stretch to stay on mixed-league rosters. Back in New York, Ramos (92 saves, 2.88 ERA since the outset of 2015) should hold the ninth-inning gig and a spot in shallow-league lineups until Familia returns from the disabled list in August. Reed owners who do not have access to Ramos can check waivers for a replacement such as Brad Ziegler, Shane Greene or Sean Doolittle.