The Arizona Diamondbacks fortified their rotation over the weekend, acquiring Trevor Cahill (and reliever Craig Breslow) from the Oakland A's for a trio of prospects: RHPs Jarrod Parker and Ryan Cook and OF Collin Cowgill.
Parker is nearly big league-ready and has big upside, having returned from Tommy John surgery to post a 112/55 K/BB ratio in 130.2 innings at Double-A Mobile and then impressing enough in a late-season cameo to earn a postseason roster spot. Diamondbacks GM Kevin Towers says the club is in "go-for-it mode," taking advantage of a window to retain top status in the NL West. However, Towers is no doubt aware that Cahill -- signed through 2015 for a little under $29 million, with team options for 2016-2017 worth a combined $26.5 million -- is a long-term buy with remaining upside.
Cahill (24 in March) has been a slightly above league-average starter to this point in his career, sporting a modest strikeout rate (5.5 K/9), average control (3.3 BB/9) and strong ground ball tendencies (54%). But the right-hander, who whiffed nearly 10 batters per nine innings as a prospect, is starting to miss more bats in the big leagues. He struck out just 11.6% of hitters faced as a rookie in 2009, but he increased that total to 15.1% in 2010 and fanned 16.3% of batters faced in 2011 (the average for starters is 17-18%).
He's getting more Ks by incorporating his breaking pitches more often. Cahill threw his his-70s curveball and his short-breaking, low-80s slider just 10 percent of the time as a rookie. As a sophomore, he threw his breaking stuff 15 percent, and he tossed a curve or slider 19 percent in 2011. Cahill is progressively doing a better job of keeping those breaking balls down, and hitters are swinging over his low curves and sliders.
In 2009, Cahill caught the middle part of the plate often with his curve and slider:
Fifty percent of his breaking balls were located low in the zone, 29 percent were thrown to the middle portion, and 21 percent were thrown high. Hitters just about never missed those middle and high breakers:
Hitters swung and missed at Cahill's curve just 22 percent of the time overall, well below the 28 percent average for starting pitchers. In 2010, Cahill did a bit better in keeping the ball down:
He threw 52 percent of his breaking pitches low in the zone, 27 percent to the middle, and 21 percent high in the zone. Those curves and sliders spotted low in the zone induced lots of whiffs:
Opponents missed 35 percent of the time they swung at a Cahill breaker. This past season, Cahill very rarely hung a curve or slider:
Cahill threw 58 percent of his breaking balls low, 22 percent to the middle of the zone, and 20 percent to the upper third of the zone. Those breaking pitches thrown to the arm side gave hitters fits, and Cahill slightly increased his miss rate with his curve and slider to 36 percent:
At worst, the Diamondbacks picked up a young, cost-controlled starter who has gradually increased his workload to 200+ innings and will complement Dan Hudson and Ian Kennedy nicely. But, with Cahill becoming increasingly comfortable using breaking pitches in addition to his quality sinker and changeup, he could yet take a leap forward and become a number two or fringe number one starter. Some think Parker has that upside, too. Still, considering that the D-Backs have an absurd amount of pitching prospects in the pipeline -- Trevor Bauer, Archie Bradley and Tyler Skaggs to name a few -- picking up Cahill is a solid move that improves the team in 2012 and beyond.