Strike thrower with electric stuff
Hernandez's calling card is his sinker, a 92-96 mph pitch that has such late, sharp movement that hitters can hardly avoid pounding it directly into the ground in front of home plate. In his career, 73 percent of the balls put into play against Hernandez have been on the ground, including just four fly balls on 33 balls in play through two starts this year. Against some ground-ball pitchers, taking balls down low and trying to force the pitcher to elevate that fastball is a good strategy for hitters, but Hernandez can throw that pitch for a strike at the knees and is just as happy to strike you out as he is to get a ground ball.
What makes Hernandez so special is that he pairs that devastating pitch with above-average secondary pitches. He went through the Red Sox lineup one time using just his fastball and breaking balls (an 83-84 mph power curve with a break almost straight down, and an 84-90 mph slider with a very sharp break and good tilt). He brought out his changeup for the second time through the lineup; he maintains his arm speed extremely well, and the pitch has tremendous late tailing action away from left-handed hitters. He has a weapon to get ground balls, a breaking ball that's effective against right-handed hitters, and a changeup that kills left-handed hitters. And he throws strikes.
By the way, he's durable, holding his velocity into the ninth inning last week; he has a big frame and broad shoulders that bode well for his long-term durability. His only real flaw in last week's game was that he would occasionally rush through his delivery and end up overthrowing his fastball, losing that sink that sets it apart. He fell into that pattern in the fourth inning, still got out of it without allowing a hit, and settled back down for the rest of the game.