4 Reasons Casey Kelly Will Make the Red Sox Wish They Never Traded Him

San Diego Padres top pitching prospect Casey Kelly will make his major league debut on Monday night against the Atlanta Braves. The 22-year-old will take Jason Marquis’ spot in the rotation after the veteran starter was placed on the disabled list with a broken left list.

After registering an 11-6 record with a 3.98 ERA, 1.398 WHIP, 6.6 K/9 and 2.9 BB/9 at Double-A San Antonio in 2011, Kelly began the 2012 season at Triple-A. Unfortunately, the right-hander made only two starts—allowing three earned runs while fanning 14 and issuing zero walks over 12 innings—before elbow inflammation landed him on the disabled list.

Kelly didn’t return until the middle of July when he logged nine innings for the Padres’ rookie-level affiliate before a promotion to Double-A. He had a 3.78 ERA with 18 strikeouts and three walks in 16.2 innings (three starts) before receiving a call-up by the Padres on Monday.

Selected by the Red Sox in the first-round (No. 30 overall) of the 2008 MLB First-Year Player Draft, Kelly began his career as a shortstop. However, contact issues and a lack of both power and speed impeded his development, and by mid-2009 the right-hander was starting games on the bump for the Red Sox’s Class-A affiliates.

So, after this past weekend’s blockbuster trade that sent Adrian Gonzalez, Josh Beckett, Carl Crawford and Nick Punto to the Los Angeles Dodgers, I thought it’d be interesting to explore how Kelly’s big league debut reflects upon the Red Sox.

Would Be Top Pitching Prospect in Organization

Prior the blockbuster deal with the Dodgers, Boston’s farm system lacked a genuine pitching prospect who was less than a year-and-a-half away from reaching the major leagues—until it acquired Allen Webster that is.

With a farm system comprised of pitching prospects RHP Matt Barnes (High-A), RHP Anthony Ranaudo (Double-A; DL), LHP Drake Britton (Double-A), RHP Stolmy Pimentel (Double-A) and LHP Henry Owens (Low-A), it’s safe to assume that Kelly would have been the Red Sox’s top pitching prospect headed into the 2012 season.

Making Debut Two Days After Red Sox-Dodgers Trade

Is it a coincidence that Kelly is making his debut the Monday following the trade? Absolutely.

Could it be a potentially painful reminder for the Red Sox as to what could have been? Absolutely.

Prior to the 2011 season, the Red Sox traded Kelly, Anthony Rizzo and Reymond Fuentes to the San Diego Padres in return for Adrian Gonzalez—the centerpiece of the recent trade with the Dodgers.

So after the Adrian Gonzalez experiment came to a disappointing end on Saturday, lasting not even two seasons, you can bet the Red Sox front office and fanbase will be closely monitoring Kelly’s debut.

Relatively Speaking, He Has a Fresh Arm

Although he received plenty of looks coming out of high school as a pitcher, the Padres drafted Kelly as a shortstop before transitioning him to a starting pitcher in the middle of the 2009 season—kindly, they offered him at-bats as the designated hitter and he frequently hit for himself.

That being said, the 22-year-old right-hander has logged only 370 innings in his four-year minor league career, with his high water mark of 142.1 coming in 2011—his first season with the Padres.

Works Low in the Zone; Induces Tons of Ground Outs

With a heavy, sinking fastball that works in the low-90s (prior to his injury earlier this season, there were reports of a velocity jump into the 93-95 mph range), Kelly has always been regarded as a ground ball pitcher.

Beyond his fastball, the right-hander’s arsenal is comprised of two secondary offerings: a curveball that’s considered his best pitch and a changeup that continues to improve.

In his four-year career, Kelly has cruised through both the Red Sox and Padres’ organizations, respectively. In his only full season at one level with the Red Sox, he posted a 1.43 GO/AO (ground out-to-fly out ratio) at Double-A Portland.

Similarly, he registered a 1.66 GO/AO in his first season with the Padres in 2011 at Double-A San Antonio.

Although he’s not a strikeout artist, there’s something to be said for his ability to keep the ball out of the air. For a starter in the pitcher-friendly PetCo Park, Kelly has the potential to be highly successful.

Along those lines, at Fenway Park, where mid-depth fly outs can carry out to left field, Kelly’s natural ability to induce ground ball outs would have been an asset in the starting rotation.