Spring training battles: The bullpen

John Rieger-USA TODAY SportsThe Royals have used the bullpen as a warm blanket the last few years, riding the dominance of "HDH" - Kelvin Herrera/Wade Davis/Greg Holland" - all the way to a pennant in 2014 and again in 2015. Gone now are Davis and Holland, leaving Kelvin Herrera to serve as the backbone to a new batch of bullpen arms.

Can the Royals continue to have a dominant pen, or even a good bullpen? Herrera should be able to slide into the closer's role without too much issue, as he did when Davis served two stints on the disabled list last season. But who will replace Herrera as the setup man? Joakim Soria, fresh off signing a three-year, $25 million contract, was a disaster in his…