The Nets said Williams has left ankle synovitis, an inflammation of the tissue, but it doesn't sound as if the injury is going to cause him to miss any games.
"We don't think it's anything serious he'll be out tomorrow for practice," Nets coach Avery Johnson said following Friday's practice, "but we anticipate having him back Sunday or Monday."
The Nets open the regular season Nov. 1 against the rival New York Knicks at the $1 billion Barclays Center.
"We've got plenty of time for him to recover and get back to work," shooting guard Joe Johnson said. "That's not a worry of ours."
Avery Johnson said the injury has been bothering Williams off and on dating to the offseason.
"Hopefully this treatment program that he's on will help him and he'll be ready to go in the next 24 to 48 hours," the coach said. "It may be something that we have to manage, but we'll see what happens after the next couple of days."
Small forward Josh Childress (left ankle), shooting guard Keith Bogans (right knee/tailbone) and center Andray Blatche (flu) all sat out of practice Friday. Avery Johnson said they're all day to day at this point.
Blatche responded to the team's official Twitter account saying he feels much better.
The Nets' $83.5 million roster heading into the 2012-13 season now stands at 15 players, meaning that Childress and Blatche -- who were signed to non-guaranteed one-year contracts in the offseason -- made the team. Non-guaranteed deals become fully guaranteed on Jan. 10, 2013.