The Nets made clear to Simmons and Paul that the organization plans to continue giving the three-time All-Star every resource necessary in the short and long term, sources said. After nearly two weeks of pain-free ramp-up, the Nets and Simmons believed he was on the cusp of playing until Simmons arrived at the team’s practice facility on Sunday reporting a return of back soreness. Simmons had been rehabilitating a herniated disk in his lower back and had repeatedly expressed his eagerness to return in the series against the Celtics and perhaps provide some defense on Boston’s elite wing players, Jayson Tatum and Jaylen Brown.