Andre Drummond, the Detroit Pistons' explosive rookie center, could miss four to six weeks with a stress fracture in his back. Drummond, 19, hurt his back attempting to block a shot in Sunday's loss to the Los Angeles Lakers. Drummond will miss the Rising Stars Challenge in Houston during All-Star weekend. Pistons GM Joe Dumars told Yahoo! Sports that he and his staff are investigating available short-term replacements in the frontcourt, and deciding if there's a player whom they believe could help them. The loss of Drummond will likely offer Russian rookie center Slava Kravtsov, who has appeared in only six games, a chance to earn minutes.