Gordon underwent arthroscopic surgery on his right knee last season. He missed the entire preseason due to the injury.
"He's going to be out," Williams said. "The way I understand it, he's going to be out indefinitely until we get some more clarity on what's going on, so I don't have to answer these questions every day and give you guys the update. We'll just go from there."
The Hornets re-signed Gordon this past offseason after matching the Phoenix Suns' four-year, $58 million offer sheet.
New Orleans opens the regular season Wednesday night against the Spurs.