On Saturday, March 15, Yoon made his Spring Training debut for the Orioles. Because of visa issues, he had not been able to pitch in games while other candidates like Gausman and Britton have impressed. If Yoon starts out in the bullpen and eventually somehow finds his way into the rotation, that wouldn’t be different to how he became one of the best starters in KBO.
1. Amateur Days
Yoon could have faded away as a non-draftee had he not received some external support. Yoon attended Yatap High School in Seongnam in Gyeong-gi province, which is located nearby south of nation’s capital, Seoul. Up to the sophomore year, Yoon was only the fourth-best starter on his team and was buried under three teammates who "exceeded 140 km/h (around 87 mph) and had ace-potential stuff that led to a bunch of mercy games versus opponents" according to his high school coach. In fact, Yoon was described to be ordinary - topping out at 131 km/h (81.3 mph) and mostly staying around mid-70’s mph. His coach had plans to put him at second base but he was "too slow to stick on that position". Yoon himself agreed that he was quite subpar. From the article, he is quoted "Even when I reflect back, I really stunk. The velocity wasn’t there and I was really average. If I were a manager, I wouldn’t put myself on the mound for game actions."
However, when Yoon became a junior, he broke out as a pitcher. The fall before that year, the coach decided to bring out the best of Yoon’s pitching ability and put him into a total workout program. As a result, the mid-70’s fastball climbed up to high-80’s and he became the ace of the Yatap High. Scouts were astounded at Yoon’s growth and he became a very attractive target to teams for the 2005 KBO Draft. According to a KIA Tigers scout, Yoon had a great showcase during a tourney in June that took place in Tigers’ home field. "If he can throw very well in the team’s home team, it wouldn’t be a bad idea to select him," said the scout. The scout also mentioned "Yoon had a very pretty delivery - ever since we picked him, we told the coaching staff not to tamper with his mechanics." The Tigers ended up taking as the first pick of the 2nd round of 2005 KBO Draft.
2. First Years And Stardom
The season after he was drafted, Yoon immediately saw the action in KBO as a reliever. For a 18-year-old, he held himself quite well: 3-4, 4.29 ERA, 7 SV in 84IP. He broke out as one of the league’s elite closer in 2006 by going 5-6, 2.28 ERA, 19 SV, 75 K’s in 94.2 IP. Fans nicknamed him "Gwangju Dam" (Gwangju is a city that the KIA Tigers are based on) in hopes that Yoon would be the perennial closer for the team for a long time. However, he switched to being a starter in 2007 (Video of his first win here). As a 20-year-old-going-21, he had decent numbers - 3.78 ERA (10th in the league) in 162 IP with 104 K’s with 54 walks allowed. But he ended up with an abysmal 7-18 win-loss record thanks to lack of support from the Tigers lineup (the team finished 8th out of the 8-team league, going 51-74 with 1 draw). 18 losses is the fifth-most in a single season in the history of KBO but given on the promise he showed as a very young starter, Tigers fans were content.
2008 was the first true big year for Yoon in multiple ways. First off, he was granted exemption from mandatory Korean military service by being a part of the Korean National team that won gold in 2008 Beijing Olympics. There is a story behind his exemption. He made it to the candidates entry for the team, but ended up not making the final entry for the last spot of the team - a Doosan Bears RHP reliever named Tae-Hoon Lim took it. Lim had a solid debut season in 2007 that earned him the Rookie of the Year Award - 7-3, 2.40 ERA, 103.1 IP, 93 K’s and 36 walks. Those are some great numbers from an 18-year-old rookie against the big guys. But when the final entry came out, Yoon was in midst of a phenomenal season, leading the league in wins (12), second in ERA (2.47) and third in strikeouts (95) by the All-Star break. On August 5, only 3 days before the start of Beijing Olympics, the Korean National team manager Gyeong-Moon Kim (who was also manager for Doosan Bears) substituted Lim with Yoon. Lim had been on a cold streak (0-1 with 9.82 ERA in 7 games after initially making the team) and had not performed well in exhibition games. At the tournament, Yoon earned 2 wins and a save while going 7.2 IP with 6 K’s as a reliever, being an integral part of the gold medal team.
Yoon continued his hot streak in 2008 and ended the year with 14-5, 2.33 ERA, 154.2 IP, 119 K’s and 45 walks. He finished second for the Golden Glove for pitchers (Note: in Korea, the Golden Glove Award goes to best player in each position, not towards the best fielders) and was chosen to be a part of Korean National team for 2009 World Baseball Classic. On the semifinals versus Venezuela, Yoon disarmed the potent lineup featuring ML’ers like Miguel Cabrera, Bobby Abreu, Marco Scutaro, etc. However, after the tournament, Yoon started to feel discomfort on his shoulder. The Tigers, alarmed about their young ace’s health, placed him in and out of the rotation. Despite the concerns, Yoon managed a decent 9-4, 3.46 ERA in 119.2 IP line but a notch down from his sublime 2008. The KIA Tigers, by the way, rebounded from horrible 2007 and 2008 and won the pennant and The Korean Series in a dramatic bout versus the dangerous the SK Wyverns. (The Game 7 of the Korean Series ended like this)
3. Few Troubles And an MVP Season
2010 posed another health threat to Yoon, but it wasn’t the shoulder. On June 18, furious with his performance versus SK Wyverns, he slammed his throwing hand in the locker room and fractured his pinky, missing six weeks. The Tigers weren’t doing well either - after his injury, the team went on a whopping 16-game losing streak. When Yoon was fully healed in August, they decided to ease him into action by putting him in bullpen. On August 15, the Kia Tigers were in a race for the 4th place spot (the lowest seed to make the playoffs) and they were playing the Lotte Giants, one of the teams that was also in the running. Yoon entered the game in relief and hit one of the league’s best hitters, Sung-Heun Hong, on the hand, causing him to miss the rest of the season. Losing Hong was a big blow for the Giants as the slugger was hitting .350 with 26 HR’s and 116 RBI’s in 110 games so far. As if that wasn’t already bad enough, only 9 days later, Yoon took the mound as a reliever versus the Giants and hit their leadoff man Sung-Hwan Cho in the head, which brought whole storm of anger from the Giants fans (Video). The saga was very traumatic on Yoon himself. According to the reports, he could not fall asleep for awhile, his appetite was gone and once he felt nauseous and was hospitalized, causing him to miss some action.
Three months after the hit-by-pitch incidents, Yoon had a chance to redeem himself as a member of the Korean National team for the 2010 Guangzhou Asian Games. In the first game versus Taiwan, when Yoon was set to pitch as a reliever in the 7th inning, the officials discovered that they accidentally left out Yoon as a part of the roster in the list. The righty was ejected without throwing a pitch. If he had pitched, the Team Korea could’ve had to forfeit the game for bringing in a player that wasn’t listed. After the Korean national team corrected their mistake, Yoon was put in to pitch against the Team Taiwan in the finals. As a reliever, he finished off the Taiwaneses by going 5.0 IP with seven strikeouts, three hits, one walk and no runs, and the Koreans won the gold. With that, Yoon managed to win back some popularity and gave hope to the Tigers fans for a better 2011 showing.
He didn’t disappoint. He had his best season as a starter (Video of his strikeout pitches) by going 17-5, 2.45 in 172.1 IP while recording 178 strikeouts (9.30 K/9) with 44 BB (2.30 BB/9). Not only that, he won the pitching triple crown (wins, ERA and strikeouts), and he led the league in K/9, FIP, WHIP, quality starts, opponent OPS, double plays induced and IP’s per start. On November 7, he garnered 61 votes out of 91 to garner the MVP award. Stuff-wise and record-wise, 2011 was the peak for Yoon.
4. Post-MVP and Shoulder Troubles
After playing seven seasons with the Tigers, Yoon was eligible to be posted to the foreign league teams and he wanted to pursue being in the Major Leagues. ML scouts were interested in him, however, the team declared that they wanted to keep Yoon for the best chance to win the pennant in 2012. He had a fine 2012, going 9-8, 3.12 ERA in 153 IP.
Going into 2013, Yoon was aware that it would be an important year - he was going to be a free agent in the season’s end and was named as the ace of the Team Korea for 2013 WBC. However, he took a loss in his only start in the tournament (vs. Netherlands) and Korea was disqualified after the first round. After the tourney, Yoon started to feel more discomfort on his shoulder. He started the season late after spending April rehabbing. But when he got into game action, he showed diminished stuff and unsatisfactory results - 3-6, 4.00 ERA in 87.2 IP. It was the lowest amount of innings thrown after converting to a starter and his worst ERA since his debut season.
Even after a subpar 2013, Yoon strongly wanted to pursue playing in MLB. For that, he hired Scott Boras as his agent and flew over to U.S. to work out for interested ML teams, which led to him signing with the Baltimore Orioles.