With Spring Training underway, baseball fans can look forward to enjoying more baseball in 2021 than we had in 2020. While MLB teams are ramping up, so are players in NPB and the KBO, Japan’s and South Korea’s top leagues respectively. NPB is starting up the earliest, on March 26, while the KBO is starting their season about a week later, on April 3. 

Both leagues will also be taking a break from mid-June through early August to allow players to represent their countries in the Olympics, which should result in both Japan and South Korea fielding competitive teams in the event. In addition to fielding Olympians, both leagues feature players that have the upside to be future Major League contributors.

Here’s a look at some pitchers from the KBO who could find their way to MLB teams in the coming years. KBO teams tend to anchor their rotations with foreign pitchers, the max being two on a team (and for most teams those are your numbers one and two in the rotation). Having standout Korean pitchers on your staff can be an incredible advantage. 

Just look at the reigning champs, the NC Dinos, with a Korean ace in Chang-mo Koo. Their top three instantly becomes one of the best in the league come playoff time. Since teams don’t use foreign players to shore up their bullpens, homegrown pitching becomes important to be able to close out games.

Starting Pitchers:

Chang-mo Koo (NC Dinos) – The left-handed Koo dominated in the first half of last season in the KBO with a 9-0 record and 1.74 ERA, and since the KBO was the first league to get underway in 2020 he received international attention for his dominance. While his fastball averaged only 89 MPH last year, he was still highly effective in the KBO with his strikeout and walk rates both making substantial positive strides, and he posted better K% (29%) and BB% (5%) in 2020 than Hyun-jin Ryu did in his best KBO season. Koo relies on his slider as his best breaking pitch, and pairs it with a splitter and a curveball to round out his repertoire.

While the rate stats have been impressive, Koo’s innings pitched have also dropped in the last few years. He threw only 93⅓  regular season innings in 2020. His career high is just 133. 

He missed a couple of months with a forearm injury last year, and his velocity wasn’t quite back when he returned, although he was able to ramp up in time to pitch in the Korean Series and make two starts, winning Game 5. Koo looks like he could be the next great Korean starter to make the jump to MLB, but he needs to stay healthy to show teams he can handle a starter’s workload. With two years until he becomes eligible to be posted and age on his side (he is only 24 years old), he has time to prove that he can do just that.

Dan Straily (Lotte Giants) – The Lotte Giants made a bit of a gamble last year on Dan Straily, as he was coming off a terrible 2019 MLB season, and they signed him to the max contract that a foreign player can sign in their first year in the KBO, at one year for $1 million. The deal worked out for both sides, as Straily was dominant and became the first KBO starter in eight years to reach the 200 strikeout mark, last accomplished by Hyun-jin Ryu in 2012. He ended the season with a 15-4 record, 2.50 ERA in 194.2 innings and a 4-to-1 strikeout to walk ratio.

Straily’s struggles in 2019 stemmed from his slider, which had been his go-to secondary pitch for his entire career, but lost its effectiveness in 2019. From FanGraphs, Straily’s slider was a positive pitch by run value in every season of his career until 2019, where it plummeted to 14.7 runs below average. 

His slider was an asset in 2020 for Lotte however, and his 36% slider usage in the KBO was higher than his slider usage was in any of his previous MLB seasons. While the slider performed better in the KBO, it is hard to tell how much better the pitch was. He hung a lot of sliders in 2019, and he appeared to miss his spots with the pitch in 2020 as well. 

The difference in 2020 was that he didn’t seem to miss belt high quite as much, and the hitters were more willing to chase it out of the zone, and miss it more frequently in the zone. This could be a quirk of quality of competition as opposed to an improvement on Straily’s part. Straily will return to Lotte again in 2021, and if he can demonstrate improved slider command he could be in line for a big league deal before long.

Aaron Brooks (Kia Tigers) – Aaron Brooks came to the KBO with much less fanfare than Dan Straily, but there are similarities in both of their journeys to Korea. Both spent part of 2019 with the Baltimore Orioles (and both struggled), and they have similar pitch mixes as well, with a fastball, slider, changeup and a little-used curveball to round out the repertoire. 

Brooks didn’t have the strikeout numbers that Straily had, but he limited walks (only 24 allowed in 151 1/3 innings), throws harder (his fastball averaged just under 93 MPH) and is more than a year younger. Brooks will turn 31 in April which means his window of opportunity is not large, but another strong performance in the KBO could give him a chance to return to the Majors, either as a back-end starter or possibly as a reliever.

Drew Rucinski (NC Dinos) – The right-handed Rucinski is one of the older players on this list (only about a month younger than Straily), which may limit his contract options in the future, but he is nonetheless one of the best pitchers in the KBO. In his two KBO seasons Rucinski has posted identical 3.05 ERAs, but his strikeout rate jumped from 16% (6.0 K/9) to 22% (8.2 K/9) from 2019 to 2020. Rucinski throws a low 90s fastball with a cutter as his primary secondary pitch, and also incorporates a slider (with vertical break that looks curvy) and a splitter that can flash good drop and fade. Rucinski also pitched very well in the Korean Series, winning Games 1 and 6, while earning a save in Game 4. He may project more as a reliever in the majors, but Rucinski could still put up some good years as a starter in Korea too.

Eric Jokisch (Kiwoom Heroes) – Eric Jokisch can seem like a pitcher from another era. The soft-throwing lefty averages 89 on his fastball, and mixes in a knuckle-curve with late break, changeup and a slider that he can manipulate to add velocity and work as a cutter inside to righties. Jokisch pitches to contact, and over his two years in the KBO he has had strikeout rates under 20% (less than 7 K/9) and a walk rate under 5% (under 2 BB/9). Despite the low strikeout totals, Jokisch did receive interest from MLB teams over the offseason before resigning with Kiwoom.

As a contact-oriented pitcher Jokisch was at the mercy of his defense, and luckily for him the Heroes were the best defensive team in the KBO. With a strong defense behind him (and Jokisch himself is no slouch, winning the Fielding Bible Award at pitcher), he was able to win the ERA title at 2.14. With the departures of Addison Russell and Ha-seong Kim, the middle infield defense of the Heroes is in question for next season, and it will be interesting to see how Jokisch has to adjust to a new defensive cast behind him. If Jokisch can continue to find success, and stay healthy (he dealt with a minor shoulder injury last year) he could find his way back to the Majors as teams are always looking for left-handed pitchers.

Min-ho Lee (LG Twins) – At this point in the list of pitchers, we are starting to look at pitchers who have potential, but still need to prove that they deserve a chance to pitch at the MLB level. Min-ho Lee definitely has potential, with a fastball that averages around 90 MPH (and can touch 94) and has a deep repertoire including a cutter, curve, splitter, and slider.

The truly impressive part about Lee’s performance is that he is only 19 years old. He spent some time going up and down from the Twins Futures League team, and he had a rough spell in August and early September where he seemed to be running out of gas (a four-start stretch where he allowed 24 earned runs, including 10 in 1 1/3 innings against Lotte on September 7). He rebounded from that rough stretch and finished the season with a 3.69 ERA in 97 2/3 innings, and should be a key member of the team’s rotation moving forward. There is still a lot of time between now and when he could be considered for a MLB role, but he could establish himself as a future MLB arm if he can keep improving in the KBO.

Relief Pitchers:

Sang-woo Cho (Kiwoom Heroes) – When I first saw Sang-woo Cho (also listed as Jo) pitch in 2019, he seemed to be MLB ready and the stats backed it up. His fastball averaged 95, and in the KBO he could dominate by just throwing a bunch of fastballs and some sliders, which feature late, two-plane movement. However, he didn’t look the same in 2020. The fastball that used to average 95 was now topping out at 95 and averaging 92, which is a worrying drop. He also dealt with a neck injury that sidelined him for two weeks early in the season, and was rested for the last two weeks of the season to prepare for the playoffs. Despite the injury, Cho set career bests with 33 saves and a 2.15 ERA.

The drop in velocity did allow Cho to deepen his repertoire, throwing more changeups which feature some fade away from lefties. He also added a splitter to give him a pitch in a different velocity range from his fastball and other offspeed pitches, though he didn’t incorporate it until later in the year and only threw it a handful of times. 

Cho has seven years in the KBO already, so he could be posted as soon as next off-season, but I doubt the market would favor a reliever with a 30-day negotiation window as dictated by the posting system. He could wait until he is eligible for free agency, and follow the path of Seung-hwan Oh by going to Japan for a couple of years before getting a chance at the big leagues. At 26 years old, Cho has time to build up his stock, and hopefully regain some of his velocity along the way.

Woo-suk Go (LG Twins) – Go (or Ko, depending on your source) has the typical fastball-slider combination that is common among relievers, and his fastball sat at 94 MPH, and touched 97 last year. Lacking an offspeed pitch to help against lefties, Go started incorporating a cutter into his pitch mix in October, and relied on it during his two playoff appearances as well, throwing it in to jam lefties or to run away from righties. His cutter control is spotty, but since it is a new pitch it will be interesting to see if his control improves following the off-season. 

He also features a knuckle-curve as his fourth pitch, but it does not distinguish itself from the slider as the pitches overlap in velocity and movement.

The surface stats from 2020 don’t do Go justice, as his ERA climbed from 1.52 in 2019 to 4.10 last year. His BB% stayed the same (10%) and his K% increased slightly (26% to 28%), but he sustained a knee injury early that caused him to miss two months, and was a bit rusty upon his return. In his first three appearances following the injury he gave up 6 runs (4 earned) in just 1 1/3 innings and allowed a run in 5 of his first 7 appearances off the injured list. He followed with 11 consecutive scoreless appearances. At 22 years old, with four KBO seasons under his belt, Go is a player to watch down the road as a possible MLB bullpen arm.

Woo-jin Ahn (Kiwoom Heroes) – The right-handed Ahn is the youngest relief pitcher on this list, at just 21 years old, but he is also the tallest at 6’3. He also has the most starting experience of the relievers, starting 20 of his 39 appearances for Kiwoom from 2018 to 2019, before being moved exclusively to the bullpen in 2020. 

Ahn has the traditional four-pitch mix of fastball, slider, curveball and changeup, though he scrapped the changeup for most of the season before bringing it back just before the playoffs. His stuff played up when he pitched exclusively out of the bullpen: in 2019 his average fastball velocity was 91 MPH in 15 starts and 5 relief appearances, but in 2020 his average velocity jumped to 95 MPH in 42 relief appearances and topped out at 99. 

The improvement showed in his stats too, as his ERA dropped from 5.20 to 3.00 (though his FIP just went from 4.06 to 3.73) and he raised his strikeout percentage by over 8 points from 20% to 29% (8.2 K/9 to 10.3). 

Like his teammate Cho, Ahn dealt with some injuries during the 2020 season, getting a late start to the year due to a shoulder problem, and missing close to a month during the season with back issues as well. Ahn is likely being groomed as Kiwoom’s next closer should Sang-woo Cho depart, but in the meantime they combine to give Kiwoom the most powerful back-end relief combination in the KBO.