The Oscar nominated actor is narrating an opening segment of the 82nd All-Star Game, airing Tuesday night on Fox.
MLB says in a statement Pitt and the segment will celebrate baseball stars from the past and present.
The 47-year-old actor stars as former baseball player and current Oakland Athletics general manager Billy Beane in the upcoming film "Moneyball," out in September.
Fox Sports says Justin Timberlake will be interviewed during the All-Star game.
The game is being held at the Chase Field in Phoenix. It airs at 8 p.m. Eastern time.