Beaubois soared to try to swat away a layup attempt by Utah's Paul Millsap on a fast break. The Mavs' first-round draft pick fouled Millsap but got the worst of the collision, crashing to the hardwood and landing with a thud.
Coach Rick Carlisle said Beaubois might have been able to return in the first half, but the rookie's back stiffened up during halftime of the Mavs' 104-92 loss. He'll spend Tuesday getting treatment in Dallas.
"Hopefully by Wednesday, he'll be OK," Carlisle said.
Beaubois is averaging 4.8 points per game and 1.2 assists this season for the Mavericks, who host the Golden State Warriors on Wednesday night.
Tim MacMahon covers the Dallas Mavericks for ESPN Dallas.