SEATTLE -- Mariners general manager Jerry Dipoto made two moves to bolster his team's bullpen for the playoff run on Monday, acquiring veteran lefty Zach Duke and cash from the Twins, then adding right-hander Adam Warren from the Yankees.
Dipoto sent Minor League prospects Chase De Jong and Ryan Costello to the Twins for Duke and $1.25 million in international slot money to the Yankees for Warren. Both players will be free agents at the end of the season.
Warren, 30, has a 2.70 ERA in 30 innings over 24 games for the Yankees this year, notching 37 strikeouts and 12 walks. The seven-year veteran has about $1 million remaining on his $3.3 million contract this season and is a former starter who is capable of multi-inning relief outings.
"Adam Warren's been a very good big league pitcher throughout the course of his career," Dipoto said. "He kind of tends to get lost in the shuffle [with the Yankees], but he's really good and it's not the first time we've tried to acquire him, it's just the first time we've been successful in trying."
Duke provides a second left-handed setup man to go with James Pazos, who became the primary southpaw after the club released veteran Marc Rzepczynski in June.
"It's nice to have two," manager Scott Servais said. "You can match up a little earlier sometimes. Pazos had a really good first half, and we used him a lot. He's still been very effective. Paz likes to come right after you. Duke does it a little differently with an array of pitches and angles and slots."
Duke is earning $2.15 million this season. The Twins sent $75,000 to the Mariners to pay down part of Duke's remaining salary, a source told MLB.com's Mark Feinsand, and Seattle will pay the rest, which is about $600,000.
Dipoto is looking to fortify his pitching staff prior to Tuesday's 1 p.m. PT non-waiver Trade Deadline, and he previously added right-hander Sam Tuivailala from the Cardinals on Friday.
"With Duke and with Adam Warren and Sam Tuivailala and even Alex Colome, to add that kind of depth to your bullpen in season is something we're pretty happy with," Dipoto said.
The question now will be where the newcomers fit in. Long reliever Roenis Elias, another lefty, will likely be sent down upon Duke's arrival.
Warren isn't as easy a decision, as the club has six right-handers: Edwin Diaz, Alex Colome, Juan Nicasio, Nick Vincent, Chasen Bradford and Tuivailala. Bradford could be the odd man out since he has Minor League options, but he's pitched well with a 2.75 ERA in 39 1/3 innings and it could come down to him or the veteran Vincent.
The 35-year-old Duke is 3-4 with a 3.62 ERA and 12 holds in 37 1/3 innings over 45 games with the Twins this year, with left-handed hitters batting .237 with 16 strikeouts in 59 at-bats. He's one of just three American League pitchers who has appeared in 30-plus games without allowing a home run.
"Zach adds both experience and left-handed depth to our bullpen," Dipoto said. "We believe he can be an importance piece for us over the balance of the season."
The Mariners will be Duke's 10th team in 14 years in the Majors.
"I had a very positive experience here," Duke told reporters in Minneapolis. "I enjoyed the area, the city, the fans. The teammates were all great. It's a very good vibe in this clubhouse, regardless of what the record says. The guys have such a great attitude every day. They get along so well. I will miss that. But from what I've been told, it's a similar atmosphere there in Seattle. So hopefully I can step in and not mess that up."
De Jong was the Mariners' No. 28-ranked prospect by MLB Pipeline, and he was 0-3 with a 6.35 ERA in seven games, including four starts, for Seattle last year. The 24-year-old has spent all of this year with Double-A Arkansas, going 5-5 with a 3.80 ERA in 21 starts and earning a spot on the Texas League Midseason All-Star team.
Costello, 22, has hit .266 with 16 home runs and 70 RBIs in 101 games with Class A Clinton this year. He was a 31st-round Draft pick in 2017 out of Central Connecticut State.
The Mariners designated Triple-A Tacoma infielder James Beckham for assignment to open a spot on the 40-man roster for the newcomers, with De Jong's departure creating the other opening. They now have seven days to trade, release or outright the contract of Beckham to the Minor Leagues.