KANSAS CITY -- Just as is the case with the Royals' lineup and rotation, the potential bullpen heading into 2018 surely will undergo more changes.
The club already has traded left-hander Scott Alexander and right-hander Joakim Soria, and lost closer Mike Minor to free agency. Expect more deals to come that could involve right-hander Kelvin Herrera, who was the closer last season before being demoted in September.
Herrera made $5.325 million last season and is in his final year of arbitration -- general manager Dayton Moore would certainly view trading Herrera as an important step in his goal this offseason of trimming payroll and restocking the farm system.
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MLB.com is taking a look at the projected bullpen of all 30 teams ahead of Spring Training. Here's how the Royals might stack up:
BULLPEN IF SEASON STARTED TODAY
Kelvin Herrera, RHP (closer)
Brandon Maurer RHP
Wily Peralta, RHP
Kevin McCarthy, RHP
Ryan Buchter, LHP
Miguel Almonte, RHP
Andres Machado, RHP
Burch Smith, RHP

STRENGTH
There are some power arms here even if the Royals do trade Herrera. Peralta, acquired from the Brewers, can bring it at 96-98 mph, as can Maurer. McCarthy (3.20 ERA in 33 games) and his heavy sinker could be a quality setup guy. Buchter offers the same type of production from the left side (2.67 ERA in 29 outings with a 0.89 WHIP). Almonte and Machado also bring it at 95-mph-plus, and Smith, acquired in a trade through the Rule 5 Draft, has touched 100 mph. The Royals do love power arms in the 'pen.
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QUESTION MARK
Who will close in 2018? Minor took over the role in September and went 7-for-7 in save opportunities, but he is now with the Rangers. Two other candidates -- Soria and Alexander -- have been traded. Herrera, if he is still here, would assume the role again, though he seems more comfortable as a setup man. If Herrera is traded, perhaps the Royals try Maurer, who closed for the Padres (33 saves over two seasons), or even Peralta, who has terrific stuff, but he has been an enigma in terms of production. The Royals do have a history of converting starters to late-inning guys (Wade Davis, Luke Hochevar).

WHAT MIGHT CHANGE
Stop me if you've heard this before: A lot could change. Moore and his staff are in rebuilding mode, so more deals could be on the way, starting with Herrera. The guess here is Maurer would get first crack at the closer's role, but don't be surprised if Peralta gets a chance to show his talent in that role come Spring Training. The Royals also are hoping some prospects (right-hander Josh Staumont) can emerge in Spring Training and claim a bullpen role. And the club is bullish on Smith as a late-inning guy.