Nah. Clinton's camp has no need to do oppo work on Sanders. Sanders is actually helping them at this point, by moving the center toward the left:
Martin O'Malley is the one who needs to take Sanders out of the game. As the LA Times article that StageManager pointed out, O'Malley sees Sanders as an impediment:
This week’s Sanders rally was the latest bit of thunder-stealing that has deprived O’Malley, the wonky former governor of Maryland and long-shot presidential hopeful, of the oxygen he needs to have any chance at the Democratic nomination. O’Malley, who formally launched his candidacy Saturday, not only faces a dominant front-runner in Hillary Rodham Clinton but is also being upstaged by Sanders, the shrewd self-styled socialist senator from Vermont who has made an early and successful play for Clinton skeptics in the party base.