Manager Brandon Hyde said Sunday that Castro is viewed as more of a bullpen piece than a starting candidate, Roch Kubatko of MASN Sports reports.
The news isn't all that surprising as Castro made only one start in each of the past two seasons, though he has typically served in a multi-inning role with 86.1 innings over 63 appearances in 2018. That should continue this season as the team looks to keep him somewhat stretched out, which could make him a candidate for spot starts when the time comes. Castro had a 3.96 ERA and 1.45 WHIP last season despite his abysmal 57:50 K:BB, thanks in part to a career-low 0.9 HR/9.