Williams, who suffered damage to the kneecap and ligaments during Sunday's loss to the Memphis Grizzlies, is expected to be fully recovered for the start of the 2024-25 season, sources said.
He is expected to undergo the procedure early next week, sources said.
Williams, who arrived as part of the Jrue Holiday trade with the Boston Celtics in September, had been a target of several teams that hoped the Blazers would consider moving him before the February trade deadline. Portland had been playing Williams along with Deandre Ayton, who arrived from Phoenix as part of the Damian Lillard trade.
Williams, 26, has shown himself to be one of the league's elite rim protectors, leading the NBA in field goal percentage allowed as the closest defender among players to defend 1,000 shots, according to Second Spectrum.
He missed the start of the 2022-23 season for the Celtics after undergoing offseason surgery on his left knee. He also tore the meniscus in his left knee in March 2022.
Williams had his best season in 2021-22, when he was a second-team All-NBA defensive selection as the Celtics made a run to the NBA Finals. He started 61 games, averaging 10.0 points, 9.6 rebounds and 2.2 blocks per game.