The Sacramento Kings were dealt another injury blow Monday.
Fox sustained a Grade 3 sprain near the end of Sacramento's practice session, according to NBC Sports' James Ham.
The floor general has averaged a team-high 18.2 points and seven assists through nine games this season, though he's connected on just 43% of his 14.2 field-goal attempts per contest.
Fox has enjoyed a relatively clean bill of health since entering the league. The 21-year-old appeared in 153 of 164 regular-season games over the past two campaigns, including 81 starts in 2018-19.
News of Fox's injury comes after power forward Marvin Bagley, another of Sacramento's foundational pieces, suffered a non-displaced fracture in his right thumb on Oct. 23.
Sacramento hosts the Portland Trail Blazers on Tuesday.