Williams suffered a sprained ankle earlier this month and it is almost certain that he will miss the remaining pre-season games, but Kidd hints that the 29-year-old could be on the sidelines for longer.
"This is going to be a question that we're probably going to have to deal with every day until he does get the green light to go," Kidd told reporters. "But we're not rushing him."
"So if we have to start the season with him still trying to get better, I think we all feel comfortable, but we would feel a little bit more comfortable if he was starting.
"If he is ready to go, he will play. We will just take it one day at a time. We got to focus on Sunday."
The Nets start their season against the Cleveland Cavaliers on October 30.