Blue Jays Add Potential to Back of Rotation in Yusei Kikuchi

After acquiring José Berríos at last year’s trade deadline and signing Kevin Gausman to a massive five-year deal in November, the Blue Jays put the finishing touch on remaking their starting rotation by signing Yusei Kikuchi to a three-year contract on Saturday. The deal is worth $36 million, with $16 million of that total frontloaded in 2022. The lefty will slot into the back of Toronto’s rotation — one that suddenly looks like a strength for a team that came just a game shy of the postseason in 2021.

That Kikuchi was available as a free agent at all was a bit of a surprise. The Mariners declined what was a uniquely structured four-year option valued at $16.5 million per year at the end of last season, and he declined his $13 million player option. Looking at his season, you can understand why. Though he started off well last year, putting up a 3.48 ERA during the first half of the season and earning the Mariners’ lone All-Star selection, he fell apart after the break, with his ERA ballooning to 5.98.

The inconsistency is something the Blue Jays will need to figure out if they want to maximize the promising raw skills that Kikuchi possesses. After debuting in 2019 with a four-seam fastball that averaged just 92.5 mph, he spent the offseason optimizing his mechanics to unlock an increase in fastball velocity. It worked: During the shortened 2020 season, he came out throwing 95 mph — the fifth-hardest fastball thrown by a left-handed starter during these past two seasons — and was able to maintain that velocity jump in ‘21. With all that extra heat, the whiff rate on his four-seamer jumped up from 15.9% in 2019 to 30.5% over the last two years.

Losing some of the effectiveness off his fastball, though, might have been one of the sources of his second-half swoon in 2021. Coinciding with the enforcement of the foreign substance ban, Kikuchi’s heater was decidedly diminished beginning in mid-June. The raw average spin rate of the pitch dropped from 2,328 rpm to 2,142 rpm, and the amount of active spin imparting vertical movement on the pitch fell drastically, too.

In concert, the pitch’s whiff rate fell from 33.6% to 28.4%, and its expected wOBA on contact rose from .496 to .515. But even more concerning than the loss of raw stuff off his fastball was the deterioration of his mechanics as the season wore on. Just look at his release point plot from last year:

Instead of a tightly bound cluster, Kikuchi wandered all over the place. His motion has never really been all that smooth; a slight hesitation at the peak of his windup and a violent leg kick in his follow-through make it hard for him to repeat his mechanics consistently. By the end of the season, you can see that he had two distinct release points:

The release point for his fastball and cutter dropped by about half an inch during the second half of the season. And as it just so happened, his two hardest pitches were thrown from one point, and his two softer pitches were thrown from the other. It might not seem like much, but you can count on batters picking up on the divergence. The lower arm slot also likely negatively affected the shape of a fastball that was already struggling with the loss of raw spin.

As Lookout Landing’s Michael Ajeto repeatedly argued last summer, Kikuchi’s best pitch is probably his slider. He gets a good amount of whiffs with the pitch — 32.5% over the last two seasons — but he wasn’t utilizing it in the most effective manner last year. Look at these two heatmaps showing the locations of his breaking ball over the last two seasons:

In 2020, Kikuchi regularly located his slider down in the zone to generate swings and misses. Last season, his breaking ball saw too much of the strike zone far too often. Batters still swung and missed at a similar rate, but when they made contact, they were able to do a lot more damage off the pitch. In 2020, they managed a .276 expected wOBA on contact off his slider; that mark jumped up to .408 in ‘21.

When we look at the entirety of Kikuchi’s four-pitch arsenal, it’s pretty easy to see the potential he showed in the first half of last year that earned him an All-Star selection:

He possesses three pitches with fantastic whiff rates, but his biggest issue is the amount of hard contact he allows when batters do connect with his pitches. His inconsistent mechanics are likely the root cause of his struggles. Beyond the potential tipping problem his two release points creates, his command is likely compromised without a repeatable delivery. He’s able to control his pitches in the zone, but his inability to hit his spots regularly led to far too many hittable pitches. In order to maximize his weapons, he should fade the usage of his cutter in favor of more sliders thrown on the edge or below the strike zone. He’ll likely continue to allow a bit too much hard contact off his fastball, but its ability to generate a high number of swings and misses means it’s a crucial part of his repertoire. But all these potential adjustments won’t mean much if he can’t figure out his mechanics first.

The Blue Jays have their work cut out for them to help Kikuchi address all these issues. But even if he grinds through another inconsistent season, the quality of his raw stuff gives him the opportunity to be a solid contributor to the back of the rotation for the next three years, with the potential for a lot more.