D’Angelo Russell’s offensive gifts are wonderful, but so far his defense has been woeful. And in the season’s early stages, it’s pretty obvious that as long as he has a hard time guarding his opponent the Nets will have a hard time winning. If that wasn’t clear before, it was crystalized in Tuesday’s loss to the Suns. “We let them do what they wanted,” Russell said. “I think it starts with me, putting pressure on the ball and stuff like that. Spencer Dinwiddie was great and made that happen.” Russell has started every game when healthy this season, all at the point since Jeremy Lin’s season-ending knee injury. But it was Dinwiddie who led the 23-2 third-quarter charge Tuesday to get the lead, and Russell who checked back in with the Nets up 106-98 with 6:35 left and saw them promptly blow the game by allowing an 18-2 run. The fact is Brooklyn’s offense has looked better with Russell off the ball, and their defense has looked better with him off the floor. The young guard’s Defensive Rating of 117.2 was not only by far the worst on the team, it was 378th of 417 players on the NBA website. He was 10th-worst among all players who had logged at least 15 minutes. Several of those worse were just bit players; with Russell a building block. It’s a long-term issue Brooklyn must fix. Russell has 6-foot-5 size, impressive length and quick hands, having shown a penchant for getting steals. But what he hasn’t done is pressure the ball the way Nets foes have this season, harassing and distracting opposing point guards. When asked if he’ll have to alter his game to do so, or simply do what he does better, he delved into the changes he’ll have to make.