According to Shams Charania in Sports, Rajon Rondo suffered a fractured right thumb.
The Lakers point guard was injured in a practice session at Walt Disney Park near Orlando on Sunday.
Rondo is expected to undergo surgery in the next few days and will miss six to eight weeks.
Due to the popularity of COVID-19, the NBA has been on vacation for more than four months. The season is scheduled to resume on July 30.
The Lakers currently maintain a 49-14 record in the Western Conference.
Since arriving in Florida, the practice on Sunday night is only their second practice.
The Lakers will have chosen Avery Bradley to withdraw from the season.
They signed JR Smith to replace him in the second half.