3 international relievers the Pittsburgh Pirates should pursue this offseason

The Pittsburgh Pirates need to improve their bullpen this offseason. What once looked like this team’s biggest strength ended up falling apart throughout the season. There’s still a solid foundation, with Dennis Santana having a huge breakout in Pittsburgh, Kyle Nicolas taking a big step forward, and the Pirates still having Colin Holderman and Carmen Mlodzinski. Even though David Bednar struggled with command throughout the year, his stuff looked as good as ever. But that represents a highly incomplete picture, with very few trustworthy bedrocks.

The Bucs should scour the free agent market to bolster their roster, but they should also take a look at what the international market could hold. They might be able to find a good reliever willing to make the move to the US and MLB, one that could take over a high leverage role in the Pirates’ bullpen in 2025 from an unexpected origin.

Raidel Martinez

Raidel Martinez has been one of the most dominant relievers in NBP for years now. The Cuban right-hander transitioned from a starting pitcher role to a reliever role during the late-2010s. He headed to Japan in 2017, playing for the Chunichi Dragons during his entire career in Asia, and has been nearly untouchable since getting there.

Dating back to the start of the 2020s, Martinez has pitched 252.1 innings, working to an ERA of just 1.11. His highest ERA in the last five seasons is 1.94, and he's finished two years with an ERA below 1.00. Martinez's WHIP comes in at just 0.78. The last time he had a WHIP over 0.90 was in 2019. The right-handed closer has struck out 30.7% of his opponents with a walk rate of 5.9%. Martinez has allowed nine home runs as well, which comes out to a HR/9 ratio of 0.32.

Now granted, NPB has become one of the most pitcher-friendly leagues in baseball. The average ERA has steadily decreased from an already low 3.83 in 2020 down to just 2.89 this year. For reference, only four qualified pitchers in MLB during the 2024 regular season had an ERA lower than the average in Japan this year.

Regardless of how pitcher-friendly NPB is, Martinez’s stuff should play well in MLB as well. His four-seamer can hit triple-digits, and he pairs that with a low-90s splitter. This pitch helps him induce a ton of grounders and keep up a strong home run rate. Martinez throws from a high vertical arm slot, and while he has long levers, he’s obviously been able to control his stuff very well.

Martinez reportedly has a chance to sign with an MLB team this offseason. He did not show much interest in forgoing the last season of his contract last offseason, according to FanGraphs. But if Martinez decides to field offers from MLB teams this winter, the Pirates should highly consider it.  He is considered a foreign professional under MLB's current CBA.

Jyun-Yue Tseng

Jyun-Yue Tseng is a right-hander out of Taiwan. He has pitched in the Chinese Professional Baseball League the last four seasons, and has been outright dominant. Tseng has a career 1.86 ERA, 0.98 WHIP, a 31.1% strikeout rate, an 8% walk rate, and a HR/9 of 0.27. He is also coming off the best season of his career thus far.

Tseng tossed 46.1 innings in 2024. His 1.55 ERA is the second lowest of his career, but he has career bests in multiple other peripherals. Tseng only handed out a walk to 7.1% of opponents with a career best K% of 34.2% last season. This bred a 4.85 K:BB ratio, the first time he has struck out at least four batters for every walk. He has given up just a single home run all year as well.

If this blurb doesn't pique your interest, his World Baseball Classic cameo answered several questions, too.

Despite his smaller stature, standing at 5’8” and 150 pounds, Tseng sits in the mid-90s, topping out at 99, with plenty of riding life. His slurve has the potential to be an above-average secondary offering. His shorter frame allows for a different look with his fastball. However, FanGraphs notes that he needs to sharpen the offering up. He can struggle with the shape of his slurve and can be inconsistent at times, which leads to some questions about his command over his breaking pitch.

Tseng is not yet considered a foreign professional under MLB’s CBA definition. He has not played six seasons of pro ball and has yet to reach the age of 25. The Pirates have a decent amount of international pool space, so they should consider Tseng as a bullpen reinforcement if he wants to make the jump to MLB.