The Seattle Mariners have been staring down a difficult decision for weeks now and it’s only getting closer as Bryce Miller nears the end of his rehab assignment.

Two factors Hyphen sees in Bryan Woo’s recent struggles

When Miller makes his return to the big league club, which is now less than two weeks away barring a setback, the Mariners will have six capable starters but only five rotation spots.

The assumption when Miller started the season on the injured list was that he would replace Emerson Hancock when he returned, but Hancock has been Seattle’s best starter thus far, posting a 2.59 ERA over seven starts while striking out batters at a career-best 28.9% clip.

Now it looks as if veteran Luis Castillo could be the top candidate to taken out of the rotation. In seven starts this season, the right-hander has produced a 6.29 ERA and minus-0.8 bWAR.

ESPN MLB insider Jeff Passan weighed in on the possibility of Castillo being taken out of the starting rotation when he joined Seattle Sports’ Brock and Salk on Tuesday.

“I think it all depends on where Luis Castillo’s frame of mind is,” Passan said. “If Luis Castillo is open to going to the bullpen, you consider that. And if he is not, then you take a look and see what his willingness to go on the injured list is. And if that’s not the case, then maybe you do consider a six-man rotation. I think there are just lots of different possibilities here.”

For Passan, what Castillo has done for the organization, which includes helping the team reach the playoffs twice, is also an important part of the equation.

“I think what also factors in is Luis Castillo has done this for a really long time at a really high level and been a really important part of the success that you’ve had organizationally, and I don’t take that lightly,” Passan said. “I think the way that you treat people who have done right by you and helped you get into the position (you’re in), they’re not disposable. So you can’t just say to Luis Castillo, you’re not performing right now, you’re going to the pen.

“Well, you could. I just don’t know how well that goes over and I don’t know what sort of precedent that sets for treatment of players going forward.”

Passan added that moving Castillo to the bullpen is the type of “cold” decision a contender has to make sometimes, but that having a productive Castillo is also key for the team.

“Having a productive Luis Castillo makes them much likelier to be a World Series team,” Passan said. “You can get rid of your manager and survive that. But knowing that Castillo has to be around still, you just need to be mindful of the way – not even the way that you’re treating him, because the way that you’re treating him is through your perspective. The question is, how does he feel like he’s being treated? That is imperative here, and if you can thread the needle and figure out a way to solve your problem while still keeping Luis Castillo content, then that’s the ideal (situation). That’s the goal, that is the aim of this whole thing. And it’s a very delicate and difficult subject.”

Castillo in line for positive regression?

While it has been a struggle for Castillo early on, Passan sees some reason to believe his numbers will level out with more starts. He pointed to Castillo’s 4.25 FIP, which is nearly identical to Bryan Woo’s and better than Logan Gilbert’s. However, he is concerned with Castillo’s career-low groundball rate.

“Ever since he’s come to Seattle, he’s been much more of a flyball pitcher. But he’s down to a 33% ground ball rate this year. Not good,” Passan said. “I will say this, the positive regression is going to come in the form of runners being stranded. He’s got a strand rate right now of only 58.8%, league average is somewhere in the 70-plus range.”

Hear the full conversation at this link or in the audio player in this story. Listen to Brock and Salk weekdays from 6-10 a.m. or find the podcast on the Seattle Sports app. 

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