Bostick was traded to the Pirates by the Nationals on Monday.
Bostick was exchanged for minor league catcher Taylor Gushue and cash considerations. The 23-year-old infielder was originally a 44th-round draft pick by the Athletics, but he exceeded expectations by showing an intriguing mix of pop and speed. His numbers dipped a good amount after being called up to Triple-A over the summer, but Bostick's .818 OPS with Double-A Harrisburg shows some promise for the future. Josh Harrison was designated for assignment to make room for Bostick on the 40-man roster.