Bell will play for the U.S. Team, while Diaz -- the Pirates' No. 11 prospect -- will be behind the plate for the World Team on July 12.
Bell is batting .318 with a .390 on-base percentage for Double-A Altoona. The 28th-ranked prospect in baseball, Bell also has more walks (33) than strikeouts (30) through 66 games. Over four seasons in the Minors, Bell has hit .303/.366/.449.
Diaz impressed the Pirates this spring with a capable bat and outstanding defense at catcher, and those traits helped him earn his first trip to the Futures Game.
The 24-year-old backstop has hit .