An MRI taken of Drummond's back Thursday revealed a stress fracture of the fifth lumbar vertebra, which means he'll miss 4-6 weeks.
"He should get better, he'll heal," Pistons team physician Dr. Ben Paolucci said before Friday's game against San Antonio. "He's not going to have anything lasting."
Drummond has already been fitted and is wearing a custom brace to help support his back while he heals.
"He's got some discomfort now," Dr. Paolucci said. "Once he gets where he doesn't have any pain, we'll be able to start some exercising program."
Dr. Paolucci said the injury, which is on the left side, occurred during the Los Angeles Lakers game last Sunday. Dr. Paolucci also indicated that Drummond had another injury to the area.
"It looks like he may have had a minor injury on the other side on the same disc," Dr. Paolucci said. "It doesn't change the treatment, it doesn't change his recovery at all."
Drummond, who had been chosen to participate in the Rising Stars Challenge in next weekend's All-Star festivities for Team Shaq, will now have to miss the event.
In 50 games this season, Drummond was averaging 7.3 points, 7.5 rebounds and 1.68 blocks in 19.7 minutes per game. He leads all rookies in rebounds and is second in blocks, fourth in steals with 0.94 per game and eighth in points.