If director Robert Zemeckis had gotten his way, "Forrest Gump" would have been very different.

The role of Lt. Dan, a platoon leader who loses his legs, was played by Gary Sinise in the 1994 film, but Zemeckis originally wanted a different -- and very famous -- actor for the part.

Casting director Ellen Lewis, who appears in the new HBO documentary "Casting By," talked with HuffPost Live's Ricky Camilleri about her work on "Gump" and revealed the actor who could have been Lt. Dan.

"I was working on 'Forrest Gump,' and the role of Lt. Dan, Robert Zemeckis very much wanted Kevin Bacon to play the role, and for whatever reason he passed on that," Lewis said.

After Bacon turned down the part, Lewis and Zemeckis went through a series of auditions with other actors. Eventually, Lewis came back around to Sinise, who had been considered earlier in the process.

"I said to Bob, 'Do you remember that I had shown you some tape on Gary?'" she said. "We got him in, he auditioned, he got the role."

Tom Donahue, who directed "Casting By," asked Lewis if she ever considered using a paraplegic actor for the part. She said she didn't for Lt. Dan, but she did use disabled actors for various roles in Martin Scorsese's "Gangs of New York."