One year ago today, Kelvin Herrera allowed what was the 8th home run he surrendered in the 2013 season, in just his 18th appearance. In total to that point, Herrera had pitched 19.1 innings, allowed 18 hits, and he allowed 10 earned runs. He also struck out over a batter per inning while keeping his walk rate at 8.6%, but giving up that many hits, and especially that many dingers is never a good thing to see from a team’s setup man.
After making one more appearance on May 22, Herrera was optioned to Omaha, where he spent about a week before a short and unsuccessful recall to the Royals. Once again the organization decided to send him to the minors, and it was at this point when Herrera’s season began to turn around. During his second stint with the Storm Chasers (and a pair of appearances with the Naturals during the Triple-A All Star break), Herrera pitched 13.1 innings, allowed just 2 earned runs on 5 hits, while walking 3, and striking out 21.
Upon returning to Kansas City, Herrera started destroying big league hitters and really never looked back. Over the final two months of the season, he pitched 30.2 innings, he allowed just 9 earned runs on 23 hits, while striking out more than 12 batters per 9 innings and walking fewer than 2 batters per 9. Those are numbers you like to see from your favorite team’s setup man.
And remember those problems with the home run ball? A week after rejoining the Royals bullpen for the 2nd time, on July 26, Herrera allowed a home run to Conor Gillaspie of the White Sox.
Since that day last year, Herrera has yet to surrender another home run.
Because of his early season struggles with the long ball in 2013, it seemed like many people had forgotten just how great Herrera is. I still see some fans express concern when Herrera enters a game in an important spot, and I just don’t get it. Even though he has done nothing but dominate since that July recall, some fans have this odd perception that he’s not an elite reliever. This perception is confusing to me, and to other people who have access to Herrera’s statistics.
In 2014, Herrera has pitched 20.1 innings with a 2.24 FIP, 1.33 ERA, 8.4 K/9, and 3.1 BB/9. It’s a few more walks than you’d prefer, but they’re far from a huge concern. And despite his relatively lower strikeout rate, there are signs that it could be picking up soon. Herrera’s swinging strike rate is currently 15.5%, which is the 4th highest rate in the league for qualified relievers. (As an aside, Wade Davis and Greg Holland are 5th and 6th in that department, respectively.)
That whiff rate is also supplemented by a Z-Contact% of 77.8%, which is the 8th best rate in the AL. For what it’s worth, Davis and Holland are 1st and 9th there. The back of the Royals’ bullpen is kind of good.
Despite those numbers showing a lack of contact, Herrera’s strikeout rate is “only” 23.5%. Due to the peripheral numbers being so excellent, and not terribly out of line with his career numbers, I would expect to see even more strikeouts coming Herrera’s way. Even if they don’t, though, he’s inducing quite a bit of weak contact, which is always going to help. He generates a high rate of ground balls and an above average rate of infield flies, which, combined with a complete lack of home runs allowed to this point, have brought him such excellent results.
Of course, having electric stuff doesn’t hurt, either. His fastball can run up to 100+ MPH with movement. His changeup averages 90.7 MPH, and has a ton of late fading action. Also, he has slightly increased the use of his curveball, and while he’s still primarily a two-pitch guy, his breaking ball does give batters one other thing to consider.
Herrera doesn’t get as much hype as Holland and Davis, but he’s still one of the best relievers in the league. His numbers suggest even more success is on the horizon, meaning those feelings of angst and despair when Herrera enters a game should only reside in opposing dugouts, and not in the homes of Royals fans.