The pair have had a feud since Rogen suggested that Entourage wasn't funny in a 2008 interview.
Ellin later insulted the comedian in the show by writing a scene in which Turtle (Jerry Ferrara) claims that Rogen's "ugliness is oddly fascinating".
However, Ellin has now told TV Guide that he originally considered Rogen for the role of Turtle.
"I'm a fan of Rogen's," he said. "I had seen him in Undeclared, and I said to our casting director, 'There's a Midwestern kind of guy who I think would be funny for this show'. But then we found Jerry, so we went that way."
Ellin also admitted that he insulted Rogen as a form of revenge, saying: "If he's going to say the show sucks, I'm going to say he's ugly."
Entourage returns for its seventh season on June 27 at 10.30pm on HBO.