The Nets used only one starting lineup for their entire preseason and finished 3-1. That success rate would suggest that coach Kenny Atkinson has found a winning combination. Yet with less than a week to go before the season opener at Indiana, he says nothing has been solidified.

“It’s just not set in stone,” Atkinson said after Friday’s practice in Brooklyn.

That means that some player has four days to break into the group that now consists of Jeremy Lin and D’Angelo Russell in the backcourt and DeMarre Carroll, Rondae Hollis-Jefferson and Timofey Mozgov up front. Allen Crabbe might be the one with the best chance to do it.

Crabbe, who was acquired in a July trade from Portland after averaging 10.7 points in 28.5 minutes and shooting .444 on three-pointers last season, wasn’t able to play in all of the preseason games because of a left ankle injury. He played in the last two and averaged 12.0 points, but Atkinson said, “We still have to integrate [him].”

Crabbe had surgery for a stress reaction in his left foot in May, and though he was back in time for training camp, he suffered the sprained ankle at the end of September. Atkinson said he has yet to have Crabbe available to him without restrictions. If he can crack the starting lineup, he likely will unseat Carroll or Hollis-Jefferson (Atkinson has heaped a lot of praise on Hollis-Jefferson).

Asked about starting, Crabbe said, “That’s what everybody’s goal should be as a player.” But he concedes he still is feeling his way. The ankle sprain slowed that process.

advertisement | advertise on newsday

“It was just more time that was off,” he said. “I was getting into the rhythm, in the groove of training camp. The first two days were good and then I went down with that.”

Crabbe said his priority is “knowing where I’m going to get my shots up — figuring out what guys like to do . . . just getting familiar with guys’ tendencies. I feel like that’ll be the biggest thing.”

Depending on how quickly Crabbe gets integrated, Atkinson might opt to stick with what has worked. As he said: “I do like how that group played together, that starting five.”

And their record is hard to argue with.