Photo: Al Jefferson's mug shot.
As punishment, the Timberwolves star center is suspended for the next two games at Dallas and at home against Houston Saturday.
"I made a very poor decision and I am truly sorry... I know that more is expected of me," he said in his apology.
Jefferson was stopped in downtown Minneapolis early Sunday for speeding and changing lanes without signaling, said officials. After he took a sobriety test, he was taken to Hennepin County Medical Center for a blood test.
Officials took him to the Hennepin County Jail for suspicion of a DWI. He was released after an hour and faces court on April 23.
Results from the blood test are expected in two to three weeks.
The trooper who arrested him said Jefferson was "very cooperative."
The 6-foot-10 Jefferson missed the final 2 1/2 months of last season after injuring his right knee and undergoing surgery.