When the Chicago Cubs promoted Starlin Castro to the major leagues in early May, some questioned whether the top shortstop prospect was ready for prime time. After all, Castro is just 20 years old, and the extent of his experience in the upper minors consists of 243 plate appearances at the Double-A level. Granted, the Dominican-born Castro raked in the Southern League (.332/.384/.482) and stood out in the 2009 Arizona Fall League, while rating as an above-average fielder by Oliver and Sean Smith‘s Total Zone. He certainly earned the admiration of talent evaluators, too — ESPN’s Keith Law named Starlin the 12th-best prospect in the game before the season, Baseball America ranked him 16th, Baseball Prospectus’ Kevin Goldstein placed him 37th and John Sickels called him a B+ prospect.
But, when the Cubs gave Castro the big league promotion, it was Sickels’ words that stuck in my head: “He needs a consolidation season and may struggle if rushed, but overall I like the balance of offensive and defensive potential he brings.” Given Castro’s inexperience, it seemed likely that he’d scuffle in 2010.
Instead, he’s holding his own as the youngest regular in the big leagues. Castro’s hitting .294/.350/.417 in 237 plate appearances, with a .326 wOBA and a 97 wRC+. His offensive numbers have been inflated by seven intentional walks, six of which have come out of the eighth spot in the batting order. Castro’s walk rate is 8.4 percent, but his unintentional rate of free passes taken is 5.5 percent. His outside swing rate, 30 percent with the intentionals, climbs to 33 percent when the IBBs are removed (28.7 percent MLB average this season). But Castro has managed not to get the bat knocked out of his hands, with a .123 ISO. The sample isn’t anywhere near large enough to pass judgment, but his D has been above-average according to UZR (+2.6 runs saved) and Oliver (+10.6). Total Zone has him at -3 runs so far. According to Fangraphs, Castro has been worth 1.3 WAR as a rookie.
For the remainder of 2010, Oliver projects Castro to bat .289/.324/.393 (.314 wOBA), while saving several more runs compared to an average shortstop. That’s pretty darned good for a guy who’d be considered young by Low-A ball standards, much less the majors. It also points to his long-term potential — Oliver has Castro reaching the three win level by the age of 24. It looks like Starlin, along with Geovany Soto and perhaps Brett Jackson, will give the Cubs strong up-the-middle production for years to come.