Roberto Osuna and the Aging Curve for Young Relievers
Way back in April, the Blue Jays turned some heads when they filled out their bullpen with a couple of 20-year-old A-Ballers: Miguel Castro and Roberto Osuna. Few doubted that these young arms had closer-type stuff, but they also lacked any experience against big league hitting. There wasn’t much of precedent for pitchers making that type of jump, making it darn near impossible to know what to expect.
The two arms went in polar opposite directions. Castro had a brief run as the Jays’ closer, but was sent back to the minors in May after a rough start. Toronto later flipped him to Colorado in the Troy Tulowitzki deal, and he remained in the minors until September.
Osuna, on the other hand, pitched brilliantly from the get-go. He took hold of the closer’s job in June after a strong start, and he never looked back. He finished the year with a 63 ERA- and 73 FIP-, both of which marks ranked in the top 35 among qualified relievers. He struck out 28% of opposing batters while only walking 6%.
The season I just described would be impressive for any reliever. But Osuna’s campaign is especially notable given his age: 20 years old. Twenty-year-old big leaguers are a rarity in modern baseball. Some of the very best prospects don’t debut until they’re 22 or 23. Kris Bryant and Noah Syndergaard are a couple of super-recent examples. Osuna was the youngest player to appear in the majors this year, and is currently the only player born in 1995 (Gosh, I feel old) to appear in a big league game.