Philadelphia star Ben Simmons has been scheduled to have an MRI on his aching back after being forced from the court five minutes into a 119-98 NBA loss to Milwaukee.
Simmons winced in pain after going up for a lay-up and hobbled from the court straight to the locker room.
Reports suggest the 76ers are concerned about the possibility of a more serious injury to the Australian guard.
He was "emotional" after leaving the x-ray room in the Bucks' arena and team officials were looking to MRI results on Monday before determining next steps, according to ESPN.
The 23-year-old recorded 17 points and six rebounds in the All-Star Game before sitting out the 76ers' 112-104 overtime victory versus visiting Brooklyn on Thursday with a balky back.
Asked was he good to go during the warm-up, Simmons said he wouldn't be playing unless he was. In the time he had on court, he made both his field goals and one of two free-throws.
Giannis Antetokounmpo had 31 points and 17 rebounds while Khris Middleton scored 25 points for the Bucks.
Antetokounmpo added eight assists for Milwaukee as they won for the 16th time in their past 18 games to improve their league-best record to 48-8.
Joel Embiid had 17 points and 11 rebounds but shot just 5 for 18 for the Sixers, who struggled to find their flow without the influence of Simmons.
Aron Baynes played about 12 minutes in his second game back from a hip injury as Phoenix won at 112-104 in Chicago.
DeAndre Ayton dominated with 28 points and 19 rebounds while Devin Booker had 29 points as Phoenix ended the game on a 17-4 run to hand the Bulls their eighth straight loss.
Baynes had four points in his limited minutes.
Hot-shooting Miami produced their best half in franchise history with 82 points on their way to a 124-105 win over Cleveland on a night Heat retired the jersey of iconic guard Dwyane Wade.
Playing without top scorer Jimmy Butler, the Heat made 14 of their first 17 shots and raced out to their best half ever by leading 82-52 at the break.
Kendrick Nunn tallied 24 points and eight assists to lead seven Miami players who scored in double figures.
The Cavaliers were paced by Cedi Osman's 19 points, seven rebounds and seven assists, while Collin Sexton added 17 points and Tristan Thompson scored 16.
James Harden scored 38 points, Russell Westbrook added 34 and Houston beat Utah 120-110 on the road for the second time in four weeks.
John Collins tied his career high with 35 points and Trae Young scored 25 points to help Atlanta overcome a short-handed Dallas 111-107.
Los Angeles Clippers appeared disjointed and unsure as they lost 112-103 at home to Sacramento and Brooklyn snapped Charlotte's three-game win streak with a 115-86 drubbing.
Australian Associated Press
