Castro, who was hitting .376 and among Southern League leaders in batting average, hits, total bases and triples, will make his Major League debut on Friday, taking over the starting shortstop position for the Cubs against the Cincinnati Reds.
The Dominican-born 20-year-old has shown consistent progress since signing with Chicago in 2007. He spent his first season in the Dominican Summer League and 2008 in the rookie-level Arizona Summer League. Last year, in his first full season as a pro, he was the Florida State League's All-Star Game MVP, and he also played in the MLB Futures Game. He got his first taste of Double-A ball, hitting .288 over 31 games. He continued to impress in the Arizona Fall League, receiving both Rising Stars and All-Prospect honors.
It was at Spring Training this season, though, that Castro garnered the most attention. He hit .429 with a homer, a pair of triples and three doubles over 16 games, playing solid defense along the way. More importantly, he showed his ability to play alongside Major Leaguers and displayed a maturity beyond his years.
"I learned something every day," Castro has said of his time in big league camp.
When Castro was assigned to the Smokies, Cubs manager Lou Pinella and general manager Jim Hendry each admitted to the media that Castro would see time in the Majors this season. His stellar performance for Tennessee, in which he scored 20 runs and plated another 20 in 26 games, and the Cubs' lackluster start to the 2010 campaign have also foreshadowed the promotion.
Castro isn't the only Cubs prospect on the move. Josh Vitters, the No. 3 overall pick in the 2007 Draft, was promoted from the Daytona Cubs of the Class A Advanced Florida State League to the Smokies.
The third baseman was a Northwest League All-Star in his first season and a Midwest League All-Star last year. He also played against Castro in the 2009 Futures Game and shared AFL Rising Stars and All-Prospect honors with him in the fall. After a slow start, he has lifted his Florida State League average to .291 -- he hit .324 over his last 10 games.