SEATTLE -- With versatile reliever Emilio Pagan and promising prospect Thyago Vieira both traded away this week in the first moves of general manager Jerry Dipoto's offseason, some are wondering if the Mariners' bullpen is suddenly getting thin.
But that was one area where Dipoto had depth to deal from, and the third-year GM feels strongly that his relief crew remains in good hands both now and down the road even after sending Pagan -- one of last season's pleasant rookie surprises -- to the A's for first baseman Ryon Healy.
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The Mariners used an MLB record-tying 40 pitchers during an injury-plagued 2017 season, and having to add so many arms to the 40-man roster at various points was one of the reasons Dipoto also dealt the hard-throwing Vieira to the White Sox for international signing bonus money on Thursday, knowing he'll need to find room for additional position players this winter.
Dipoto sees 23-year-old closer Edwin Diaz heading a group of youngsters who should keep Seattle's bullpen in good hands, along with veteran setup man Nick Vincent and late-season acquisition David Phelps, plus lefty specialist Marc Rzepczynski. Shae Simmons showed he could help as well after getting healthy at the end of last year, and Tony Zych is another reliever who expects to return at full strength.
"We feel pretty good about the group we have with the combination of the younger guys -- Diaz, Dan Altavilla and James Pazos," Dipoto said. "And the big strides taken by Art Warren and Matt Festa this summer and fall have been notable, along with the recent drafts of Seth Elledge and Wyatt Mills."

Warren, a 24-year-old right-hander and the Mariners' No. 17 prospect, opened eyes in the Arizona Fall League regular season by allowing no runs and just five hits with 12 strikeouts in 11 1/3 innings against some of MLB's top prospects. He had a 3.06 ERA in 43 games for Class A Advanced Modesto this past year and appears to be rising through the depth chart.
Festa, Seattle's No. 18 prospect, is another 24-year-old who threw well for Modesto and in the Fall League. Mills, 22, was a third-round pick out of Gonzaga this past June and is ranked as the Mariners' No. 22 prospect. Elledge, 21, was a fourth-rounder out of Dallas Baptist and is Seattle's No. 20 prospect. Both Mills and Elledge pitched well at Class A Clinton and have joined the crop of up-and-coming right-handers.
"There's a good number of guys ages 22-26 that are something from super-high impact in quality like Edwin Diaz to knocking on the door as what we think are future building blocks," Dipoto said. "Right-handed bullpen is a place we felt we had a little depth, and we turned some of that depth into a first baseman, which was not an area we were quite as flush."
Dipoto said Max Povse (club's No. 8 prospect), though he's been starting in the Fall League, is another pitcher who could compete for a bullpen role as he develops. And depending on what happens with the rotation this winter, right-handers Erasmo Ramirez and Andrew Moore and lefties Marco Gonzales, Ariel Miranda and Andrew Albers could be bullpen candidates as well if they don't crack the starting five.
Ramirez and Gonzales are both out of Minor League options, so they'd almost certainly open the year in the 'pen if they aren't starting.
The ever-active Dipoto may well add more arms to the mix in the coming weeks, but Seattle's options already are lining up for what figures to be intriguing competition next spring for the seven or eight bullpen spots to open the season.