Nuggets head coach Michael Malone told ESPN during the game broadcast that Barton told him he felt something pop in the hamstring. Barton will undergo further evaluation on Saturday.
Barton pulled up awkwardly after driving to the basket, grimacing as he passed the ball to a teammate. He hobbled his way over near the Nuggets' bench and went down on the baseline.
Malone was the first to check on Barton as the veteran guard grabbed at his leg and writhed in pain. He exited the court, and shortly thereafter, Denver ruled him out for the game.
Without key players, the Warriors snapped Denver's four-game winning streak.
"I think all you guys are fishing for we lost this game because of Will's injury," Malone said in his postgame media session. "Don't make that excuse for us. Will Barton went down. He's hurt, and we feel for him. But we all get paid on the 1st and 15th. Do your job. We didn't do our job tonight."
The Nuggets have been hit hard by injuries in recent weeks, losing three key players in the past six games. Star guard Jamal Murray recently suffered a season-ending ACL surgery, and backup point guard Monte Morris strained his hamstring earlier this week.
Barton is an important part of Denver's offense with his slashing and scoring ability, adding a dynamic isolation option to Nikola Jokic's floor game.
Barton, 30, is averaging 12.9 points, 4.1 rebounds and 3.3 assists in 55 games this season.