Golden State Warriors guard Chris Paul broke his hand during his team's 113-109 victory over the Detroit Pistons.
Paul sustained the injury in the third quarter on Friday and was unable to return to the court, with his team later saying he needed surgery.
The 38-year-old joined the Warriors in June and is averaging 8.9 points and 7.2 assists across 32 matches this season.
"I feel so bad for Chris," said Warriors coach Steve Kerr.
"I know he's had a couple of hand surgeries before, I believe, maybe on the other hand.
"I saw him holding it and instantly was worried. So I feel terrible for Chris, but obviously guys will step up and be ready to play.
"We've got to hold down the fort without him."
The Pistons' miserable season, which included them equalling the longest losing run in NBA history, continued with this narrow defeat.
Warriors star Stephen Curry scored 14 of his 26 points in the fourth quarter to help overturn the Pistons' 103-102 lead late on.
Elsewhere, the Los Angeles Lakers slumped to a fourth straight defeat with a 127-113 loss to the Memphis Grizzlies.
Marcus Smart scored 29 points, including eight three-pointers, and Jaren Jackson Jr added 31 points as the struggling Grizzlies sealed a second win in six games.
LeBron James scored 32 points and Anthony Davis 31 but it was not enough to revive the Lakers' poor run of form which has seen them lose 10 of their past 13 games.
Paolo Banchero starred in the Orlando Magic's last-gasp 122-120 victory over defending NBA champions the Denver Nuggets.
The Nuggets held an 18-point lead at the end of the third quarter but the Magic fought back, with Banchero making four free throws in the final 34.6 seconds to secure the win as he finished with 32 points, 10 rebounds and 11 assists.
Meanwhile, the Boston Celtics thrashed the Utah Jazz 126-97, with Jayson Tatum scoring 30 points, Kristaps Porzingis adding 19 and Jrue Holiday 14.
Anthony Edwards and Karl-Anthony Towns starred as the Minnesota Timberwolves sealed a thumping 122-95 win over the Houston Rockets. Edwards scored 24 points while Towns added 22 as well as eight rebounds and six assists.
The Indiana Pacers' 150-116 victory over the Atlanta Hawks included a franchise-record 50 assists, with 18 of them dished out by Tyrese Haliburton who also scored 10 points and claimed eight rebounds.
