Now the real work begins for the Nuggets in trying to retain their starting center.

Nene will opt out of the final year of his contract worth nearly $12 million and, as a result, become an unrestricted free agent, a source familiar with the situation said Wednesday night.

It means Nene can sign with any team he wishes without the Nuggets getting a chance to match the offer when free agency begins after the expected NBA lockout, which likely will start Friday.

Nene had until today to make a final decision.

The Nuggets tried to sign him to a contract extension before today, the last day of the NBA’s collective bargaining agreement, but to no avail. Instead, Nene figures to have many suitors — including the Nuggets — as he explores his options.

Nene opted out of the final year of the six-year, $60 million contract that he signed in 2006.

Nene repeatedly has said he would like to retire in a Nuggets uniform. But he expressed concerns about his situation in a wide-ranging interview with The Denver Post after the season.

“I’ve been here for nine years,” Nene, 28, said in early May. “If that doesn’t work how you want it, you need to sit down and evaluate everything and see what you can do.”

The Nuggets figure to be a prominent player in the Nene sweepstakes this summer or fall, whenever NBA free agency begins. The 6-foot-11 Brazilian has played his entire NBA career with the Nuggets and has said he enjoys living here. His wife, Lauren, is from Colorado. They are expecting their first child, a boy, in July.

Nene is coming off arguably his best season. He averaged 14.5 points and 7.6 rebounds, almost career-high production in both categories. He shot 61.5 percent from the field, a career high, and 71.1 percent from the free-throw line.

During his career, Nene has overcome numerous injuries and a bout with cancer to be a solid contributor as the Nuggets’ only true post player.

Last Thursday after the NBA draft, Nuggets executives Masai Ujiri and Josh Kroenke said they wanted Nene back with the team. They have made keeping Nene a priority, meeting with him and his agent to settle any differences and get back on the road to retaining the former first-round pick. Nene, the No. 7 overall selection of the 2002 draft, has NBA career averages of 12.3 points and 6.9 rebounds.

“Nene is a player that we want to have here for a long time,” Kroenke said. “He’s been a backbone of ours for the last several years, and he’s a big part of our future.”

Chris Dempsey: 303-954-1279 or cdempsey@denverpost.com