The Mets should consider signing Yusei Kikuchi

The Mets need pitching help. Jacob deGrom and Max Scherzer make the most formidable rotation duo in the big leagues, but relying on consistency from an oft-injured ace and a 37-year-old with 2,500 career innings pitched may not be a winning bet. The same goes for Carlos Carrasco and Taijuan Walker, both brilliant pitchers at their peak whose recent injury history should concern the team. There’s also no clear fifth starter, which means at this point the Mets are going to have to turn to one or more of Tylor Megill, David Peterson, Trevor Williams, or Jordan Yamamoto for multiple starts.

Fortunately for the Mets, there are ways of acquiring pitchers before the season starts, though the likelihood of landing a splashy candidate after an active autumn seems pretty low. Signing a free agent pitcher to fill the back end of the rotation seems more likely, and a pitcher the team should heavily consider signing is Yusei Kikuchi.

After three seasons spent with the Seattle Mariners, Kikuchi at this point is probably best known for going to the same high school as Shohei Ohtani, but when he entered the league many considered him the best Japanese pitching import since, uh, Shohei Ohtani. That buzz wore off quickly after a disappointing rookie season in 2019 where he went 6-11 with a 5.46 ERA in just over 160 innings, registering a pedestrian 80 ERA+ and 0.5 bWAR for the last-place Mariners. He struck out few batters and gave up a lot of home runs, neither admirable qualities for a pitcher in this era, or any era, really.

His performance improved slightly in 2020, but not enough to consider his Seattle signing a sudden success. With the important caveat of the shortened season attached, Kikuchi went 2-4 with a 5.17 ERA, good for a still-pedestrian 83 ERA+ in 47 innings. His strikeout rate improved and so did his home run rate, but his walk rate worsened and he leveled out as about the same pitcher he was in 2019.

Kikuchi didn’t exactly justify his hype in 2021, but in his age-30 season he showed flashes of what made him so captivating in Japan. He struck out ten Giants through six innings in his first start of the season and continued his progress through an impressive first half of the season. Through sixteen starts before the All-Star Break, Kikuchi amassed a 6-4 record and only failed to reach at least six innings pitched in two of his appearances. His best start of the season came in late April against the eventual pennant-winning Astros where he gave up only one hit and zero runs through seven innings. It was the type of performance he had only put up once or twice in his career, only this time they were happening more consistently, and it was enough to earn Kikuchi his first All-Star nod.

And then the wheels fell off, as Kikuchi earned only one win in his thirteen second-half starts, finishing the season at 7-9 with a 4.41 ERA, certainly better than in previous years but nothing to marvel at. Kikuchi’s durability proved useful over 157 innings pitched, but his 94 ERA+, while the best of his career, still fell below average. If this story sounds familiar to Mets fans, it's because Kikuchi had an eerily similar season as Taijuan Walker, who also parlayed first-half success into an All-Star appearance before falling off in the second half. Their overall numbers from 2021 look strikingly alike, as well:

While Walker’s second-half nosedive is most likely explained by a nagging oblique strain he suffered in May, Kikuchi’s regression is less clear, though some suspect he may have suffered from MLB’s midseason sticky stuff crackdown. Whatever the case may be, his stuff did not play nearly as well in August and September as it did in April and May, and the Mariners shut him down for the last two weeks of a pennant chase while just missing the postseason.

But that doesn’t mean that Kikuchi doesn’t deserve a look in free agency. He’s not the most appealing of the remaining free-agent starters, but he arguably has the greatest upside outside of Carlos Rodón and at least a few more years of effective pitching left at just 31 years old. His left-handedness also makes him an attractive and potentially versatile pitcher, as an opportunity in long-relief or left-handed high leverage appearances awaits him should he falter as a starter. But perhaps the biggest reason the Mets should give Kikuchi a shot is that he’s improved as a starter every year he’s pitched, and in a rotation filled with instability, penciling in 150 innings from a still-improving once-phenom seems like a great use of a fifth starter role.