Brooklyn Nets guard James Harden is out indefinitely after sustaining a setback during his rehabilitation from an injured right hamstring, the team announced Tuesday. "We're back to square one," Nets coach Steve Nash said. "He will be back when he's back. It might be the playoffs. It might be sooner." The 31-year-old was re-injured during an on-court session, according to the team. He underwent an MRI exam Tuesday to learn the severity of the injury. Harden is averaging 25.4 points, 8.7 rebounds and