The Pirates acquired Hassell from the Nationals on Thursday in exchange for cash considerations or a player to be named later.
Hassell was just outrighted off the Nationals' 40-man roster earlier this week, and now he's on the move to a new organization. The 24-year-old outfielder has slashed just .215/.304/.289 over 63 games this season at Triple-A Rochester after sporting a .223/.257/.315 slash line in 70 major-league games in 2025.