The Nets used the exact same starting lineup throughout the preseason, but coach Kenny Atkinson insists that’s no guarantee it will remain the same when they open the regular season Wednesday in Indiana. Jeremy Lin and D’Angelo Russell are the first-choice backcourt, and Timofey Mozgov is the presumptive starter at center. But who will get the nod at the forward spots? And will pricey small forward Allen Crabbe — whose $19.3 million salary this season is tops on the roster and fifth highest in team history — really be on the bench? “It’s still to be determined,” Atkinson said. “Still have to look at everything, and he’s a part of that. [We’ll] look at his progression. That being said, I do like how that group played together, that starting five. But nothing is set in stone yet.” That group included newcomer DeMarre Carroll at small forward, with Rondae Hollis-Jefferson having settled into the power-forward slot. Carroll had his best years with the Hawks when Atkinson was the lead assistant. He may never be the prototype 3-and-D guy he was in Atlanta, but after two seasons with the Raptors when he was plagued by knee woes, the 31-year-old has looked sprier this preseason than he ever did in Toronto. “It’s the best I’ve felt. I felt like I can move more,” Carroll said. “One, my shot felt good, more legs. It’s amazing how good you can feel when you’re actually healthy.” Carroll started every game in the preseason at small forward, with Hollis-Jefferson at the four. Hollis-Jefferson averaged 10.5 points and 5.8 rebounds in the preseason. Now that he’s gotten to work closer to the basket, his 67.9 field-goal percentage was second-best in the NBA. Both are regarded as solid defenders, but Hollis-Jefferson admits his jumper needs work. Yet if Atkinson wanted to opt for more offense, he could easily slide Carroll to power forward and go to his bench for more shooting on the wing.