As a 22-year-old rookie in 2012, Kelvin Herrera made more appearances than any other Royals pitcher and led all relievers with 84.1 innings pitched. That’s a lot to ask of a guy, but luckily, he’s well-equipped for the role.
In those 84.1 innings, Herrera struck out 77 and walked just 21. Batters hit the ball on the ground 55% of the time.
In other words, he’s good.
So good, in fact, that he earned a spot on Baseball America’s All-Rookie Team.
Armed with a fastball that went as high as 103 mph this year (and had the highest average velocity in the majors), he’s got a good chance to be dominant. His walkrate tells us that he’s able to command where he puts the ball, and, much to the chagrin of many hitters in the league, he has a changeup that’s not only strong, but has been called the filthiest pitch among relievers all season.
Of course, this is nothing we didn’t already know. Back in August, I took a long look at the pitch’s effectiveness. Set up by a fastball that requires batters to cheat, his changeup drops to the mid-80s. Considering it also tumbles down and in to right-handed hitters and down and away from lefties, it’s the perfect complement.
How’d you like to be that batter, geared up for triple digit heat in a full count and have to adjust to the 86 mph change that falls off the table? Can’t imagine that’s a lot of fun at all. Half of his strikeouts have been on changeups, even though he throws them less frequently than the fastball with two strikes. – Kings of Kauffman, Kelvin Herrera’s Nasty Changeup
He was one of the more valuable relievers in baseball with 1.9 fWAR and 2.3 bWAR (and according to Fangraphs, only seven relievers are more valuable, including teammate Greg Holland).
Interestingly, two of Herrera’s teammates were mentioned in the article about filthiest pitches. Tim Collins‘s curveball and changeup had more movement than any other reliever and Luke Hochevar‘s cutter rated as the best among big league cut fastballs (though the Royals don’t want him to throw it, for some reason). Before the 2011 season, Buster Olney proclaimed Hochevar’s slider one of the most valuable in the game. Perhaps it’s a mix up in classifying pitches that would both be thrown hard and both would have horizontal movement – but it also makes you wonder how Hochevar can’t figure it out with such an arsenal.
But Herrera can. There’s a chance the Royals may look at him as a starter some day, and he has the pitches to succeed there. That probably won’t happen next season, as he forms part of a formidable late-inning combo with Holland and could fill in as closer if necessary. Getting more innings out of him as a starter would increase his overall value, but he has a history of arm troubles while in the minor leagues that must be making the Royals hesitant to move him there.