KIA Tigers Rookie Seong-yeong-tang Shines In Breakout Season

KIA Tigers fans have witnessed a remarkable transformation on the mound this season, with rookie right-hander Seong-yeong-tang (21) turning heads across the league and establishing himself as one of the most promising arms in Korean baseball. Though his 2025 campaign has been cut short for strategic reasons, his dazzling performances and rapid development have left both his coaches and fans eager for what’s next.

Seong-yeong-tang’s journey this year has been nothing short of meteoric. After debuting in 2024 as a relatively unheralded 10th-round pick—96th overall—he entered the 2025 season as a project, but quickly became indispensable in the KIA bullpen. By May, his command and stamina had shown noticeable improvement, and he’d worked his way from a developmental player to a full roster spot, contributing in both middle relief and high-leverage situations.

“I had the most fulfilling first year,” Seong-yeong-tang reflected after his early season wrap-up. “It was tough at times, especially with the team’s struggles, but I always took the mound determined to get the job done, no matter my role.” According to KIA manager Lee Beom-ho, the decision to end Seong-yeong-tang’s season early wasn’t taken lightly. “He pitched a lot this year. We’re starting a recovery program for him in the Futures League. Young pitchers need to be mindful of their pitch counts and innings. He threw quite a bit in the minors before joining us, and with so many innings in the first team, we felt it was best to cut him off at 50 innings this year.”

The numbers speak for themselves. Over 45 games and 52.1 innings, Seong-yeong-tang posted a 3-2 win-loss record, 7 holds, and a glittering 1.55 ERA. Batters hit just .209 against him, and his WHIP stood at a stingy 0.97. He allowed only 13 walks, translating to an impressive 2.24 walks per nine innings—a testament to his control. His pitch arsenal, featuring a fastball, curveball, and cutter, kept hitters guessing all season. Notably, his fastball reached a peak velocity of 147 km/h (91 mph), with an average of 144 km/h (89 mph) on his changeup. That’s a serious uptick from his early days, and a sign of the hard work he’s put in.

“My velocity went up as the season progressed,” he explained. “Early on, my average wasn’t great, but by the end I was sitting in the mid-140s. In high school, I threw a fastball, curve, and forkball, but as a pro, I’ve focused on a two-seamer, curve, and cutter, using the pitch tunnel to my advantage. The analytics team suggested I try a cutter breaking away from my two-seamer, and it worked out really well.”

One moment stands out for Seong-yeong-tang: his two-inning, two-strikeout perfect outing against SSG Landers on August 28 in Incheon, where he retired the top six batters in order. “Originally, I thought my debut was the most memorable, but that SSG game really stuck with me. I was just grateful for every chance to take the mound, especially in tough situations.”

Manager Lee Beom-ho didn’t hold back in his praise, calling Seong-yeong-tang “the biggest surprise of the season.” He added, “He stepped up when the team needed him most. If he keeps improving his speed and learns how to manage his workload, he’ll be an even better bullpen asset.” That’s high praise, especially considering Seong-yeong-tang’s modest draft pedigree.

The decision to end his season wasn’t just about rest—it was about protecting a valuable asset. Including his 25.1 innings in the minors before his call-up, Seong-yeong-tang logged 77.2 innings this year. With the Tigers’ playoff hopes fading and the risk of overuse injuries looming, the coaching staff opted for caution. “The team’s ranking has dropped, so it’s a bit disappointing,” Seong-yeong-tang admitted, “but I’m grateful to the coaches for all the experience they gave me.”

Throughout the season, he’s been lauded for his stamina and ability to maintain velocity deep into games. His approach? “I’ve focused on control since I was young. I wanted to use the pitch tunnel more, and I practiced a lot to make my delivery consistent. I’m still working on my changeup, especially for left-handed hitters. It’s something I want to bring into games more next year.” He’s also set a lofty goal: “I’d love for my top speed of 147 km/h to become my average next season.”

With the regular season winding down, the KIA Tigers are facing an uphill battle to reach the postseason. As of September 22, 2025, they sit at 68 wins, 4 draws, and 66 losses, with a .507 win percentage—good for fifth place, just behind the NC Dinos. The team has eight regular-season games left, including crucial matchups against SSG Landers on September 23 and the NC Dinos on September 27 and 28. The Tigers have a 7-6-1 record against SSG and are tied 7-7 with NC this year, so every game counts as they chase a playoff berth.

As Seong-yeong-tang shifts his focus to recovery and preparation for 2026, another storyline is emerging: the future of foreign ace Adam Oller. Oller, who has pitched 138 innings over 24 games with a 10-6 record and a 3.59 ERA, is also battling for a new contract. After missing July with elbow inflammation, he’s returned to form in September, but his performance down the stretch could determine whether he dons the Tigers’ uniform again next year. “I want to stay with KIA next year,” Oller has said multiple times, but he’ll need to hit the innings threshold and deliver in his final outings to secure that chance.

For the Tigers, the bullpen has become a focal point in their late-season push. With Seong-yeong-tang’s emergence and Oller’s steady presence, the team has the pieces to compete—if they can string together wins in the final week. The coaching staff’s careful management of young arms like Seong-yeong-tang signals a commitment to both immediate results and long-term success.

Seong-yeong-tang has promised to come back “even stronger and scarier” next season. With his blend of velocity, control, and poise under pressure, there’s every reason to believe he’ll deliver. For now, Tigers fans can only wait and watch as the team battles for its postseason hopes, knowing that the future of their pitching staff looks brighter than ever.