The Nets declined to extend the rookie contracts of three eligible players by Monday’s 6 p.m. deadline, most notably returning leading scorer Cam Thomas. 

Injured center Day’Ron Sharpe and offseason pickup Ziaire Williams also were eligible but did not receive extensions, according to Post beat writer Brian Lewis. 

The 23-year-old Thomas is the most notable of the three after he averaged a team-best 22.5 points per game in 66 appearances last season.

The third-year guard is slated to earn $4.04 million this season. 

A large Nets contingent attended the Liberty’s title-clinching win Sunday night, praising their WNBA sister squad and the electric atmosphere at a sold-out Barclays Center. 

“I was there. It was amazing,” first-year coach Jordi Fernandez said. “Very proud of the team, the organization, a game that wasn’t easy because there was adversity, there was pressure, you could feel it. 

“But that was the definition of a team that every player did whatever it took to win the game and I was very happy to be a part of history and win a championship here in Brooklyn. … It was just great for the city, great for the business, great for women’s sports.” 

Liberty stars Sabrina Ionescu and Breanna Stewart connected on just 5 of 34 combined shot attempts — including a 1-for-13 night from 3-point range. But they pulled out a 5-point victory in overtime against the Minnesota Lynx for the first league championship in team history. 

Ben Simmons logged 51 minutes over three preseason appearances after undergoing season-ending back surgery in March. 

Fernandez was asked what he can “reasonably expect” from the three-time All-Star point guard, who has appeared in only 57 NBA games in the past three seasons. 

“Just the same as what I’ve been expecting from him,” Fernandez said. “Come to work every day, positive energy, committed, willing to push the basketball. 

“He’s one of our floor generals, a true point guard, so he’s done a great job. He’s getting back to the healthy Ben Simmons that we all know. He’s done a great job. I’m very happy with him.” 

Fernandez said Trendon Watford hasn’t returned to practice but “will most likely at some point next week.” The fourth-year forward has been out since early October with a hamstring injury. 

“He’s doing a great job with his recovery and we’ll have a better update, but we’re expecting early next week to return to practice,” Fernandez said.