SAN DIEGO — It appears the Mariners have made a decision on Yusei Kikuchi’s next start and what pitcher they will bring up to supplement the innings needed to cover the shortened outing.
Monday afternoon in Albuquerque, Class AAA Tacoma used an opener for its final game of the road trip, starting lefty reliever Matt Tenuta for one inning. Rainiers manager Daren Brown then brought in top prospect Justus Sheffield, who was scheduled to start the game, to pitch in the second inning.
While the use of an opener has become common at the major-league level for various reasons, this usage was likely to prepare Sheffield to do the same thing against the Rangers at T-Mobile Park on Friday, when Kikuchi pitches just one inning for his scheduled start.
Sheffield pitched three innings, allowing one run on two hits with three walks and two strikeouts. He threw just 46 pitches.
While manager Scott Servais said on Sunday he wasn’t ready to commit to Kikuchi making a one-inning start in his next turn in the rotation, the development with Sheffield seems to indicate that he and general manager Jerry Dipoto have made the decision. Dipoto said on his podcast “The Wheelhouse” that Sheffield would be the likely candidate to be called up when they decided to limit Kikuchi for a start.
Kikuchi made his sixth start of this season on Saturday. He’s posted a 1-1 record with a 4.68 ERA, while throwing 32 2/3 innings, striking out 23 and walking eight. His past four starts have come on four days rest, which is a change from the five days of rest that he got in between starts while pitching in Nippon Professional Baseball.
When Kikuchi signed as a free agent in the offseason, Dipoto discussed a throwing plan where Kikuchi would make a one-inning start once a month to control his innings workload and also keep him healthy. The Mariners are very cognizant of Japanese pitchers adjusting to the heavier workload and shorter rest in MLB and the injuries that often arise a year or two into that transition.
“He’s pitched 160-180 innings over the last couple years in Japan, so we’re not going to get super conservative,” Dipoto said at Kikuchi’s signing news conference. “But we do feel over the course of 30-32 starts of a season, if every sixth start we back off — so roughly once a month — we make that more of a bullpen day where he throws a nice healthy bullpen between, stays on turn and prepares as a normal start, and then goes out and throws a one inning or 30-pitch start, it gives him a nice little breather without breaking turn or taking him away from his routine.”
The Mariners have been doing this with younger pitchers in their minor-league system and will consider doing it with top prospects like Sheffield and Justin Dunn.
Kikuchi’s agent, Scott Boras, discussed such a plan with the Mariners when they were negotiating the four-year, $57 million contract.
“These guys are in their early to mid-20s and we’re just seeing the Tommy Johns rack up,” Boras said. “We’re also seeing a performance level where the players with the greatest durability were the guys coming over at 30 or 31. So I really felt with a player of this ability, we had the opportunity to restructure a new format to acclimate him to this environment. With Jerry being a former pitcher, we raised this and talked about the data, and said let’s do something that will help you long term and help the player to acclimate to a five-day program with rest stops maybe in the fifth or sixth start and limit innings. Jerry was all for it.”
With Erik Swanson replacing the injured Wade LeBlanc in the starting rotation and lefty Roenis Elias taking on more of a high-leverage role in the bullpen, Sheffield was the obvious choice to be called up to piggyback off Kikuchi.
The Mariners don’t want to crush a bullpen that has already struggled to cover middle innings with a full bullpen day. Instead, they’ll bring up their top prospect, who is stretched out to 90-plus pitches if needed.
Sheffield hasn’t been as sharp as expected with the Rainiers. He’s posted a 0-1 record with a 3.93 ERA in three starts and the relief appearances. In 18 1/3 innings, Sheffield has allowed eight earned runs on 13 hits, including four homers. He’s struggled with his fastball command and pitch efficiency, walking 14 batters with 11 strikeouts.
The corresponding roster move to get Sheffield on the roster could be interesting. Their only reliever with minor league options is right-hander Ruben Alaniz. But his spot in the bullpen was expected to be filled by right-hander Chasen Bradford, who is likely to be activated from the disabled list during the two-game series vs. the Padres.