Jarrod Parker Debuts For Diamondbacks by Tommy Rancel September 29, 2011 Lost in the shuffle of Tuesday night’s historic comeback by the Arizona Diamondbacks was the major-league debut of D-Backs prized prospect, Jarrod Parker. A top-10 selection in the 2007 draft, Parker missed the entire 2010 season after undergoing Tommy John surgery. Despite the injury, Marc Hulet ranked him as the No. 1 prospect in Arizona’s system prior to the season, saying he might be major-league ready by the end of 2011. During the summer Mike Newman — our other prospect guru — had the opportunity to scout Parker. In his write-up, Newman said Parker’s fastball sat 92 mph to 96 mph with the ability to hit higher velocity, on occasion. As far as secondary options, Parker relied on his changeup more than his previously rated plus-slider, perhaps as a byproduct of his continued recovery. Like Hulet, Newman thought the 22-year-old Parker was ready for MLB action this year. With 5.2 innings of shutout ball on Tuesday, Parker looked ready— even though his debut was not Strasburg- or Moore-esque. After missing the 2010 season, Parker’s workload is being closely monitored. Because he is basically at the end of his pitch and innings limits, he threw just 73 pitches against the Dodgers. Meanwhile, even in the small sample size, we saw exactly what Mike and Mark were talking about. True to the scouting report, Parker averaged 92 mph to 93 mph with his fastball and maxed out near 96 mph. Also true to the report, his changeup was his secondary offering. Of the 20 non-fastballs he threw, 11 were changeups, five were sliders and four were curveballs. With the changeup, he generated eight strikes — including two swings and misses. Disguised with fastball arm-action, Parker’s changeup came in at an average of 12 mph less than his fastball. Although we are talking about a relatively small number of pitches, I was intrigued by the off-speed pitch; particularly how Parker used it. The changeup is generally used as a neutralizer against batters of the opposite hand. Shawn Marcum — among others — has drastically reduced his platoon splits with an effective changeup. In his debut, Parker actually used the change more against right-handed batters than he did against lefties. And nearly all of his secondary pitches were thrown against righties — including all of his sliders and curveballs. A 73-pitch outing in late September generally means little, especially for an Arizona team focused on the playoffs. On the other hand, for a team on the rise, Parker looks like a fantastic addition to a young, talented rotation led by Ian Kennedy and Dan Hudson. In addition to his stuff, Parker executed a sound game plan and looked like more like pitcher than simply a hard-thrower. While his career might have temporarily been derailed by injury, Parker’s future as a front-line starter appears to be back on track.