This story was excerpted from Sonja Chen’s Dodgers Beat newsletter. To read the full newsletter, click here. And subscribe to get it regularly in your inbox.
LOS ANGELES -- For much of the first half, the Dodgers haven't had a consistent idea of what to expect from either Roki Sasaki or Emmet Sheehan on any given turn through the rotation.
The overall body of work has been similar for both. At present, Sheehan looks to be trending in a better direction after allowing one run in 4 1/3 innings to the Padres on Sunday. Sasaki has reverted to his early-season struggles, most recently allowing six runs in three innings on Thursday in the series opener with San Diego.
Though both have worked through their fair share of issues this season, neither Sasaki nor Sheehan has really cost the Dodgers. And neither has had a real risk of losing his job in the rotation.
"Roki hasn't had a lot of repetitions on the Major League side," manager Dave Roberts said. "Emmet has, but just finding ways to be a little bit more efficient. … I think we've seen a lot of good things from both those guys, and they're going to continue to get their opportunities."
Over the past few weeks, Roberts has been more upfront about Los Angeles needing to see better results from Sasaki and Sheehan. But at the same time, if L.A. wants to keep its six-man rotation that has allowed for so much of the team's success this season, there's no better alternative.
A big reason for that is that Blake Snell (surgery to remove loose bodies from left elbow) and Tyler Glasnow (lower back spasms) are both on the injured list. Snell is making steady progress, throwing bullpen sessions and getting closer to facing hitters. Glasnow is farther behind, as his back has shut down previous attempts to ramp up, although he is playing catch now.
At the end of the progression for each, Snell and Glasnow will need to fully build up on rehab assignments, which should take at least four appearances to reach the desired five-inning/75-pitch threshold.
The Dodgers' other starting-pitching depth on the 40-man roster has not been immune to the injury bug. No. 6 prospect River Ryan is on the Minor League IL with a left hamstring injury for the second time this season. Gavin Stone (right shoulder inflammation) and Landon Knack (right intercostal strain) both began the season on the IL.
So through all their ups and downs, Sasaki and Sheehan have had plenty of runway. And there are different things to take away from both.
Sasaki had a fantastic peak, recording a 2.55 ERA across six starts from May 2 through June 5. During that span, his triple-digit fastball velocity returned and his new, harder splitter enhanced the rest of his pitch mix. But in his past four starts, his velocity has ticked down some and his command has lapsed. The results have matched that, as he's allowed 19 earned runs in his past 17 innings.
"Maybe because of my intensity of fastball or maybe my command issues," Sasaki said through interpreter Ken Okubo on Thursday, "so I feel like I have to work on those things to get better."
Sheehan's stuff has generally graded out well, but that hasn't consistently translated into results. His fluctuating fastball velocity has given him less margin for error, but his slider has been elite, contributing to him ranking in the 90th percentile of the Majors in chase rate (35%) and in the 87th percentile in whiff rate (30.8%) entering Sunday.
"Trying to go deeper into ballgames is really important for a starter," Sheehan said. "Just execution-wise, a lot of delivery thoughts in the first half. I think second half, just focusing more on executing pitches and getting guys out."
Even with Sasaki and Sheehan being question marks at various stretches this season, the Dodgers’ rotation ranks third in ERA (3.32) and second in innings (506 1/3) in MLB. That's one big reason why they feel good about betting on the upside of their young arms, rather than searching for alternatives with internal reinforcements on the way.