BOSTON -- The Red Sox added the impact bullpen arm they've been searching for, completing a trade with the Mets on Monday for righty Addison Reed in exchange for three pitching prospects.
The deal was finalized less than an hour before the 4 p.m. ET non-waiver Trade Deadline.
The move comes on the heels of Red Sox president of baseball operations Dave Dombrowski getting a right-handed bat with plenty of defensive versatility last week in Eduardo Nunez, who has made an instant impact with Boston.
Reed has served as the Mets' closer for most of the season, filling in for the injured Jeurys Familia. For Boston, he will become the primary setup man in front of stud closer Craig Kimbrel. The reliever will be added to the roster in time for Tuesday night's game against the Indians.

"We like him a lot," Dombrowski said. "We think he can come in and be a premium setup guy for us. He makes us deeper in our bullpen, pushes other guys back to pitch earlier in the game."
Long the topic of discussions with multiple teams, Reed is heading to Boston in exchange for three right-handed pitchers: Stephen Nogosek, Jamie Callahan and Gerson Bautista, the Red Sox's 18th-, 23rd- and 28th-ranked prospects by MLBPipeline.com.
Though there was some chatter even after the deal for Nunez about the Red Sox adding a bat to an offense that has performed below expectations since the All-Star break, Dombrowski didn't see a fit on the market. Top prospect Rafael Devers has added a boost in recent days and the Red Sox now need some of their regulars to start hitting at their expected levels.
"We didn't feel there were any other real impact bats out there that made us significantly better," Dombrowski said. "And I know [manager] John [Farrell] talked about the same thing, we've talked about it -- sometimes your own club has to step up at times. We know that some of the guys are better than what they've been playing. They're good players, and we look for them to step up."
With the Red Sox entering Monday's game against the Indians a half-game behind the first-place Yankees in the American League East and Reed (a free agent after the season) expendable for a Mets team out of the postseason race, both teams were highly motivated to make this deal a reality.

The Yankees, who acquired third baseman Todd Frazier and setup man Player Page for David Robertson a couple of weeks ago, snagged righty starter Sonny Gray from Oakland on Monday.
"Yeah, I think the Golden State Warriors have significantly made some moves. I expected it," Dombrowski quipped. "I would have been surprised if they didn't. But I think [Yankees general manager] Brian [Cashman] probably has made them the Golden State Warriors and we're the significant underdogs, when I'm listening to the MLB Network."
At the Winter Meetings, Cashman called the Red Sox the Golden State Warriors of baseball after they acquired Chris Sale, Tyler Thornburg and Mitch Moreland on the same day.
"So it kind of switched," said Dombrowski. "I would anticipate, like he said earlier in the year that he didn't know how the Red Sox would lose a game, I think it'll be the same. I don't know how they'll lose a game right now. They made some good moves. They made their club significantly better. It didn't surprise me at all. It was out there for an extended period that they were looking to do those things."
The Red Sox focused on what they could do to get better. Dombrowski went on an exhaustive search for a righty setup man, inquiring about no fewer than 20 of them before securing the deal with one of his top targets in Reed.
Reed has turned into one of the finest relievers in the game after joining the Mets in a waiver trade in August 2015, notching a 2.09 ERA over 145 games. In 48 appearances this season, the 28-year-old has a 2.57 ERA with 19 saves in 21 opportunities.

Reed's closing experience is invaluable, as the Red Sox will now be in a better position to get Kimbrel rest when needed.
"The fact that we've been able to strike a deal, get Addison in here, days in which Craig might not be available, Addison certainly is that closer B so to speak. His addition is a welcome one," said Farrell.
Reed joins Matt Barnes and Richard Hembree as Farrell's top setup options. Joe Kelly will again be prominent in that mix when he returns from a left hamstring strain that forced him to the disabled list earlier on July 15. The Red Sox are also hoping to get sidewinder Carson Smith back in the near future. The righty hasn't pitched since undergoing Tommy John surgery in May 2016, but he did throw off the Fenway mound Monday.
To get the reliever they coveted, the Red Sox came up with three quality arms for the Mets, who were in need of replenishing their pitching depth on the farm.
"I talked to [Mets general manager] Sandy [Alderson] quite often over the last couple of days and finally said, 'OK, this is what's going to get it done. Let's go ahead and get it done.' I've dealt with Sandy -- I hate to say this -- for about 30 years," said Dombrowski. "So we've dealt with each other for a long time, and I know when he tells me something from an honest perspective, he means it. So we went out and got the deal done."
Fantasy spin | Fred Zinkie (@FredZinkieMLB)
Reed (2.57 ERA, 1.12 WHIP) should provide helpful ratios for AL-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, AJ 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.