Ricky Rubio will start in his place.
Russell entered the day averaging 19.9 points and 5.3 assists per game in his first full season with Minnesota.
The Timberwolves have other offensive weapons including Karl-Anthony Towns, Malik Beasley and rookie Anthony Edwards, but the team will suffer if the one-time All-Star misses an extended stretch. With at least 15 missed games in three of Russell's first five seasons, any injury should be concerning.
It's been a whirlwind career for the 24-year-old, who is already on his fourth team since being drafted No. 2 in 2015.
After a big year with the Brooklyn Nets in 2018-19, the guard moved to the Golden State Warriors last season and remained productive while averaging 23.6 points and 6.2 assists per game. They flipped him to Minnesota before the trade deadline and helped a struggling team with averages of 21.7 points and 6.6 assists per game.
He is expected to play a key role for a franchise that has just one playoff appearance since 2004.
The latest injury could open more playing time for young guards Edwards and Jarrett Culver, while Rubio should take on a bigger role in running the offense.