Simmons will be out of action and considering his treatment options, according to the team.
Simmons appeared to tweak his knee when he came down with a rebound midway through the third quarter. Simmons seemed to be concerned with his knee a few moments later before slowly walking back to the locker room.
Simmons had been playing well in a new position for the team since the tipoff of play in the NBA bubble, showing he can be productive in the power forward spot.
Now, Simmons will be out as the Sixers try to move forward without him in their lineup.