ESPN's Adrian Wojnarowski reported the news Saturday after the 2019-20 All-Star missed Friday's victory over the Houston Rockets. He'll also sit out games against the Chicago Bulls on Sunday, the Detroit Pistons on Tuesday and the Boston Celtics on Thursday.
Siakam was a breakout star during the Raptors' run to the 2019 NBA championship, and he's continued to develop into a vital piece of the team's core. He's averaged 20.1 points, 7.5 rebounds, 4.8 assists and 1.2 steals across 30 appearances during the 2020-21 season.
The 26-year-old Cameroon native has been mostly durable throughout his five-year NBA career, though he's been sidelined this season by minor groin and knee injuries.
Chris Boucher should join Toronto's starting lineup to fill the void. Yuta Watanabe and Stanley Johnson also figure to receive added minutes as part of the frontcourt rotation.
The Raptors have considerable scoring depth, which could help them avoid a major drop-off, but they don't have a frontcourt player who can match Siakam's overall impact.