ESPN's Adrian Wojnarowski reported the news Thursday, noting the Kentucky product will undergo further testing. Wojnarowski later noted Cousins left the court after "bumping knees" with another player.
Cousins played 30 games last season for the Golden State Warriors as he recovered from a ruptured Achilles he suffered during the 2017-18 campaign with the New Orleans Pelicans. He signed a one-year deal with the Lakers in July.
Any setback is sure to raise flags given Cousins' injury history and how important he could be for the Lakers as they pursue their first playoff appearance since the 2012-13 season.
Cousins hasn't played more than 75 games in a season since he was a rookie in 2010-11, and he struggled to replicate his All-Star form during his one year with the Warriors. He averaged 16.3 points, 8.2 rebounds and 3.6 assists in 25.7 minutes across 30 regular-season games.
The Lakers took a chance on him this offseason as a potential complement to LeBron James and Anthony Davis.
At his best, Cousins is a four-time All-Star and two-time All-NBA selection who has averaged as many as 27.0 points and 12.9 rebounds at times throughout his career. Adding someone like that alongside James and Davis makes the Lakers all the more formidable in their quest for an NBA championship.
However, Cousins' health concerns and overall effectiveness remain worries as he ages.
If he is forced to miss time because of this knee injury, Los Angeles will turn toward JaVale McGee and Jared Dudley for additional minutes in the frontcourt alongside Davis.