Andrew Bogut limped out of his Cleveland Cavaliers debut on Monday after sustaining a leg injury during his new team's clash with the Miami Heat.
The Australian veteran collapsed to the court early in the second quarter after colliding with Heat forward Okaro White.
Bogut was helped to the locker room by his teammates, clearly attempting to avoid putting weight on his left leg.
The Cavaliers said Bogut would play no further part in the game and would undergo examinations to determine the extent of the injury.
Bogut only joined the Cavaliers last week after being freed from his contract with the Philadelphia 76ers after a trade with the Dallas Mavericks.
The 32-year-old 7-footer (2.13m) is in his 12th NBA campaign after being the top overall pick in the 2005 NBA Draft.
His arrival had been seen as giving the Cavaliers' roster a key inside player with championship experience.
Bogut, a three-time Olympian with Australia, had helped the Golden State Warriors beat the Cavaliers in the 2015 NBA Finals.
He was released from the Warriors last year after Golden State reshuffled to accommodate Kevin Durant.
Bogut earlier Monday denied his decision to join Cleveland was a way of getting back at the Warriors.
"Everyone's going to try to ramp up that story -- nice try -- it's one of those things," he said.
"I don't hold any grudges and moved on and I'm in a good place, and we'll see how it goes."