Immediately after missing out on the Roki Sasaki sweepstakes in the offseason, the Philadelphia Phillies dipped their toes into the international market with the signing of Japanese pitcher Koyo Aoyagi. Six months later, the team put an end to the experiment, as they parted ways with the 31-year-old, according to MLB.com's Todd Zolecki, after a rough stint in the minor leagues.
After officially being posted last December, Aoyagi joined the Phillies one month later in January following a successful nine-year stint with the Hanshin Tigers of the Nippon Professional Baseball (NPB) league. As a member of the Tigers, Aoyagi posted a 61-47 record to go along with a 3.08 ERA in 154 games, primarily as a reliever. He was named to three All-Star teams and led the league in wins twice in 2021 and 2022. Most recently with the Tigers, he helped to lead the team to a Japan Series championship victory in 2023.
Phillies released Koyo Aoyagi after disappointing results in minors
With the recent successful wave of players to come out of Japan including Shohei Ohtani, Yoshinobu Yamamoto, Kodai Senga, Seiya Suzuki and several others, the Phillies had high expectations for Aoyagi, per Zolecki, and he was expected to compete for a spot in the back end of the bullpen.
This did not come to fruition, however, as he struggled mightily in limited action in spring training, giving up four runs in three innings of work. Following a tough spring, he was sent to Triple-A Lehigh Valley, where his struggles continued as he posted an ERA of 7.45 in 19 1/3 innings. Soon after, he was demoted to the Double-A Reading Fightin Phils and his performance did not improve. He pitched to a 6.91 ERA and 1.74 WHIP in 14 1/3 innings in Reading, which ultimately led to the end of his Phillies tenure.
Aoyagi is not the first Phillies international signing to struggle with the team in recent years. Some fans may remember the late Miguel Alfredo Gonzalez who joined the team in 2014 when he signed a three-year $12 million contract with a vesting option for the 2017 season. Gonzalez only ended up pitching for the Phillies briefly in the 2014 season as a September call-up before tragically passing away in 2017.
Had Aoyagi made the Phillies' roster, he would’ve been the third Japanese player to wear red pinstripes for the team, following So Taguchi and Tadahito Iguchi, both of whom played for the team during the 2008 World Series championship season.
As the Phillies look to bolster the bullpen ahead of the trade deadline, it is now clear that Aoyagi will not be in the picture going forward. Given his track record in the NPB, it is possible that he will get a second chance to prove that he belongs in the major leagues elsewhere.