Arizona Diamondbacks' right-handed starting pitcher Merrill Kelly started the first World Series game in his career, and dang, it was a good game. Kelly pitched seven innings, allowed one run, struck out nine Texas Rangers, and didn't allow a single free pass. Not only was Kelly dominant in his first World Series start, but he's been a crucial member of this team and pitching staff all year and Postseason. But it wasn't all that long ago Kelly's career came to a stall. At one point, it looked like he may never become anything other than minor league depth. But here we are in 2023, and Kelly has become one of baseball's most underrated starting pitchers.
Kelly's journey into pro ball was convoluted. He was drafted three times. The first time was in 2007 by the Baltimore Orioles in the 37th round. The second time was by Cleveland, this time in the 22nd round in '09. Kelly did not sign either time, as it would be his third time through the draft he would land a deal. In 2010, Kelly was taken in the 8th round out of Arizona State by the Tampa Bay Rays and signed for a mere $125K.
Kelly would then spend the next five years in the Rays' system. Despite being known for their pitching development, Kelly wasn't one who suddenly went from mid-round draft pick to MLB starter overnight, like the Rays have done countless times over. Although Kelly was solid throughout his time in the minor leagues, he was never considered a top prospect. Kelly even went through the Rule 5 draft without getting selected. Going into 2014, his last season in affiliated baseball prior to signing with the D-Backs, Kelly wasn't even considered a top-30 prospect in the Rays' system.
After the 2014 season, the Rays released Kelly. At 26 years old, Kelly had a choice to make; he could try and resign with another MLB club, hang them up, or go overseas. Kelly chose option C and spent the next four seasons in South Korea. In 729.2 innings for the SK Wyverns, he worked to a modest 3.86 ERA, 3.11 K:BB ratio, and 1.31 WHIP. Kelly never had a K% above 24%, but his highest single-season walk rate in South Korea was just 7.1%.
This was enough for some MLB teams to show interest in the right-hander during the 2018-2019 off-season. Kelly opted to return to his roots and sign with the Arizona Diamondbacks. Making his debut at age 30, Kelly's first three MLB seasons were solid. He owned a 4.27 ERA, 4.30 FIP, and 1.28 WHIP in 372.2 innings. Kelly continued to be a low-strikeout sort of pitcher with a 20.2% K-rate but still carried a quality 6.6% walk rate. Home runs, however, were an issue as he had a 1.33 HR/9 rate.
At 33 years old and in his fourth MLB season, Kelly finally broke out. Throughout 2022, Kelly worked to the tune of a 3.37 ERA, 3.65 FIP, and 1.14 WHIP. He upped his K% to 22%, though his walk rate took a slight turn in the wrong direction to 7.6%. However, his home run rate dropped a significant amount to just 0.95. Kelly followed that up with another quality season and one that was arguably better than his breakout campaign.
Before we talk about Kelly's 2023 season, you can't go without mentioning his repping Team USA in the World Baseball Classic. Kelly pitched the Championship game of the WBC, and while he got dinged up in his start, it just goes to show how far he made it up to this point in his pro baseball career.
This past year, Kelly posted a 3.29 ERA, 3.85 FIP, and 1.19 WHIP. His walk rate took another spike to 9.4%, but he struck out 25.9% of opponents while carrying an above-average 1.01 HR/9. Kelly turned in one of the lowest ERAs in the league, clocking in at 11th. But overall, he had the 24th-best fWAR among all starting pitchers.
And now, after a winding road from 37th-round draft pick to underrated MLB starting pitcher, Kelly is on baseball's biggest stage and dominating. He has pitched 24 innings this Postseason and has allowed just six earned runs. That is good for a 2.25 ERA. He has struck out 28 batters, while only eight have been able to reach via free pass. Kelly is a fierce competitor and has shown that, both on the mound and off the field.
Over the last two seasons, Kelly has a better ERA than Aaron Nola, has more fWAR than Clayton Kershaw, and a lower WHIP than Kevin Gausman. Despite his dominance in 2022-2023, Kelly has not been named to an All-Star game, nor has he received a Cy Young vote. I don't see how one could argue against him being most underrated pitcher in the National League.
Kelly is a great feel-good story. He went from a late-round draft pick to a KBO pitcher, and now he's back in the United States, dominating in the Postseason. If Kelly starts another game and pitches like he did in Game 2 of the World Series, you may see him win World Series MVP if (and when, yes, I know that's bold, and I already knocked on wood) the Diamondbacks take home the trophy.