The Class A West Virginia Power were sapped Friday.
Outfielder Josh Bell, the Pirates' second-round pick last June and the Power's No. 3 hitter, underwent surgery to repair the meniscus in his left knee. Rated by MLB.com's as Pittsburgh's No. 4 prospect, he's expected to miss at least a month.
Bell, a 19-year-old switch-hitter, was batting .274 with six extra-base hits and 11 RBIs in his first 15 games as a pro. The Irving, Texas, native slugged his first homer and collected a career-high three RBIs on April 11. He last played on Tuesday, when he was lifted after trying to stretch a single into a double in the third inning of a 14-5 loss to Savannah.
The procedure was performed in Pittsburgh by Dr. Patrick DeMeo, according to MLB.com. Bell, who received a $5 million signing bonus, will begin his rehabilitation at the team's complex in Bradenton, Fla., also known as Pirate City.