The team will be giving away bobbleheads in the likeness of the former Dodgers right-hander, and he will throw out the ceremonial first pitch.
Hershiser apparently asked D-backs manager Kirk Gibson, who was a teammate of Hershiser's on the 1988 World Series-winning Dodgers, to catch the pitch.
Gibson, who hit the game-winning homer in Game 1 of the World Series, said he politely declined.
"I'm a Diamondback," Gibson said. "I'm the manager of the team. I respect Orel tremendously. He knows that. It's not disrespect towards him. If I was out of baseball I would have done it, but I'm in baseball and I've got different colors on tonight and tomorrow."
The Dodgers will honor Gibson on July 31 with a Gibson bobblehead giveaway. The D-backs are scheduled to be in Los Angeles to play the Dodgers that night.