Argenis Diaz, who has attended Spring Training as a member of the 40-man roster in each of the last two years, hit .253 (70-for-277) with 14 doubles, 24 RBIs and 21 runs scored with Double-A Portland this year. The 22-year-old shortstop entered the season rated by Baseball America as the "Best Defensive Infielder" in the Red Sox minor league system.

"Argenis Diaz is an intriguing shortstop prospect who projects to play above-average defense with soft hands, good first step quickness and an above average throwing arm," said Pirates GM Neal Huntington. "He is developing on the offensive side of the baseball, but Argenis quickly becomes the best defensive shortstop prospect in our system."

• Diaz was originally signed by the Red Sox as a non-drafted free agent on July 22, 2003.
• He has been rated as the Boston organization's "Best Defensive Infielder" since 2006 when he joined the Gulf Coast League Red Sox after playing in the Venezuelan Summer League the previous two years.
• Last year the native of Guatire, Venezuela raised his batting average and slugging percentage for a third consecutive season after hitting a combined .284 with 52 RBIs in 110 games between Single-A Lancaster and Double-A Portland.

See Argenis Diaz' stats and bio page at MiLB.com »