The Warriors were comfortable winners over the LA Clippers in Game 1 on Saturday night, with Cousins finally making his playoffs debut after nine years in the league.
But disaster struck early on in Game 2 when Cousins chased down a loose ball.
The 28-year-old grabbed a steal and went to race down the court, only to lose his handle and then crumble to the floor in immediate pain.
Cousins knew something was wrong straight away as he clutched his left quad.
The four-time All-Star limped off to the locker room to further evaluate the injury.
And the Warriors have since announced that he will undergo an MRI within 24 hours to learn the full extent of the issue.
Cousins only made his Warriors debut in January of this year after recovering from a torn left Achilles he suffered while with the New Orleans Pelicans last season.
He looked to be showing signs that he was returning to his best in the latter stages of the campaign, highlighted with a 28-point game against the Denver Nuggets earlier this month.
Fortunately, it doesn’t seem the fresh injury concern has anything to do with his former issue.
But the Warriors will be waiting anxiously for the results of the MRI to see whether Cousins will be out of the playoffs for a long period of time.
Cousins’ absence would mean a bigger role for Kevon Looney and Andrew Bogut, who the Warriors signed last month.
Bogut only played two minutes in Game 1 against the Clippers while Looney played 17.