General manager Jim Rutherford said Williams will have surgery this week and is expected to be sidelined at least four months. Rutherford said Williams injured the tendon in his right leg while running during an off-ice workout three days before the start of preseason camp.
The 26-year-old Williams -- one of the team's most durable players and a key member of the No. 1 line that also includes star center Eric Staal and left winger Ray Whitney -- was already coming back from knee surgery that cost him 43 games last season.
"You can't really tell [how that injury had healed] until you get in a number of games," Rutherford said. "He looked good, his conditioning was good -- he really appeared ready to go again. But that's going to be set back for a while now."
It is the latest injury setback for the Hurricanes, who are hoping to have captain Rod Brind'Amour back in the lineup for the start of the regular season. Brind'Amour underwent surgery to remove torn cartilage from his left knee on Tuesday.
It is the same knee that required reconstructive surgery in February after he tore his anterior cruciate ligament, an injury that sidelined him for the rest of the season.
Williams tore the anterior cruciate ligament in his left knee in December, and that injury ended a string of 205 consecutive games played since March 2004, the fourth-longest streak in franchise history.
He returned for one game -- skating fewer than four minutes of a critical loss at Washington in April that helped keep Carolina out of the postseason -- but did not play in the Hurricanes' final two games. Williams finished last season with nine goals and 21 assists.
The injury will certainly challenge the depth that Rutherford has spent the offseason strengthening.
The team's revised depth chart showed second-line right winger Patrick Eaves elevated to fill Williams' spot, though Rutherford said there's now an opportunity for fourth-line forwards Ryan Bayda and Chad LaRose and ex-Carolina forward Jeff O'Neill, who is attempting a training-camp comeback.
"We'll keep all options open. I'm not going to rush into doing anything," Rutherford said. "We've talked about our depth and felt our depth was stronger now. It's going to be tested. We're going to find out for sure."
Rutherford could also trade one of the eight defensemen the Hurricanes have signed for this season. Carolina placed much of its emphasis this offseason on shoring up a blue line plagued last season by spotty play. The Hurricanes dealt forward and fan favorite Erik Cole to Edmonton for defenseman Joni Pitkanen, signed Josef Melichar and reached new deals with Tim Gleason and Dennis Seidenberg.
"But I don't think I will look at that option for some time," Rutherford said. "We have to hope all goes well, and if the time of this is at the minimum, then Justin's still going to play 30 games for us."