Curry is out with a left leg injury, while Durant, who was traded to the Suns on Wednesday night, continues to recover from an MCL sprain in his right knee. Williamson has a right hamstring strain.
Since Durant, Curry and Williamson were selected as starters for the All-Star Game on Feb. 19 in Salt Lake City, the league has elevated Philadelphia center Joel Embiid, Utah forward Lauri Markkanen and Memphis guard Ja Morant into the starting lineup.
Fox, who will be making his first All-Star Game appearance, is averaging 24.2 points and a career-high 4.3 rebounds for the Kings this season.
Edwards also will be making his All-Star Game debut, averaging career highs in points (24.7), rebounds (6.0), assists (4.6) and steals (1.6) for the Timberwolves this season. He leads the NBA with 96 steals and in minutes played.
Siakam made the All-Star Game during the 2019-20 season. The veteran is averaging a career-high 25.0 points and 6.2 assists per game with the Raptors. He also is averaging 8.0 rebounds.