Andre Drummond won’t be playing in the BBVA Rising Stars Challenge at All-Star weekend – and he might not be suiting up for the Pistons until late March.

The back injury Drummond said he incurred in attempting to block a Steve Blake shot during Sunday’s loss to the Los Angeles Lakers at The Palace has been diagnosed as stress fracture of the fifth lumbar vertebra. Drummond, who saw Pistons team doctors on Thursday and underwent further testing on Friday, will be out four to six weeks, according to Dr. Ben Paolucci, Pistons team physician. The regular season ends on

April 17, which would be roughly a month after Drummond could be ready to return.

The injury was discovered by way of an MRI exam Drummond underwent on Thursday.

If there’s a silver lining, it’s that a stress fracture should have no residual effects, Paolucci said. In other words, unlike disc injuries that often lead to chronic back trouble, once the stress fracture is healed, it’s healed.

Once Drummond is “asymptomatic, doesn’t have any pain,” Paolucci, who said Drummond’s injury is “not uncommon,” said he would be able to begin on exercise programs. He estimated that process could take four weeks. Drummond has been fitted with a custom brace, he said.

Lawrence Frank met with reporters before the Pistons released the extent of Drummond’s injury, though Frank already knew of his status.

“I know what the story is,” he said. “He went to see a doctor today. We’re fully aware of what it is, wrapped our arms around it. We’ll just move forward.”

Over 50 games, Drummond has shown steady – and often remarkable – improvement from a player the Pistons weren’t certain would be ready to crack the rotation when training camp opened. He averaged 7.3 points and 7.5 rebounds in 20 minutes a game and emerged as an impact player at both ends with his instinctive offensive rebounding skills, his elite ability to finish at the rim and his athleticism defensively giving the Pistons the rim protector they’d sought since the glory days of Ben Wallace and Rasheed Wallace.

Drummond played on Monday against New York, one day after suffering the injury, but was shut down at halftime when he informed the training staff that he was having difficulty getting his back loose. He felt better on Wednesday, but four minutes into his stint against Brooklyn, Drummond absorbed a charging foul from Brook Lopez and landed on his tailbone, exacerbating the injury, he said afterward. He didn’t return to the game.

Drummond saw Pistons team doctors on both Thursday, sitting out practice, and went through more tests on Friday that determined the nature of the injury.

With Drummond sidelined, Frank will weigh his options for the frontcourt rotation. Slava Kravtsov is the player who most closely approximates Drummond’s skill set as another athletic 7-footer who has a track record as a shot-blocker in Europe. But Kravtsov has played sparingly this season, just 24 minutes spread out over six games. Eleven of those minutes came in Wednesday’s loss to Brooklyn, when he scored four points and grabbed two rebounds.

“That’s why you carry three centers,” Frank said before Friday’s game with San Antonio. “It’s a great opportunity for Slava. He’s putting a lot of work in. He’s been extremely professional.”

Frank could also attempt to alter the rotation so that Jason Maxiell, though undersized, plays backup minutes to Greg Monroe at center while Charlie Villanueva and Jonas Jerebko fill in at power forward. Jerebko has been playing as Kyle Singler’s backup at small forward since last week’s trade that shipped Tayshaun Prince and Austin Daye to Memphis and brought point guard Jose Calderon to Detroit from Toronto.

“We’ll also need more from Greg, more from Max, Charlie and Jonas,” Frank said. “That’s the NBA – next man up.”