Harrison Barnes had until June 29 to mull over a $25 million player option for next season, and it appears the veteran forward has made his decision.

NBC Sports California confirmed Tuesday that Barnes informed the Kings that he'll walk away from the final year of his deal and become an unrestricted free agent.

ESPN's Adrian Wojnarowski was first to report the news.

According to a league source, Sacramento is confident it can keep Barnes in the fold with a new long-term contract, although the former Maverick and Warrior has the ability to sign with any NBA team once free agency begins June 30. 

[RELATED: Barnes looks back on India trip]

With Barnes opting out, the Kings' salary-cap figure just dramatically shifted. Sacramento has just under $42 million in guaranteed contracts for this season, leaving the team with close to $67 million in available cash to spend. 

Barnes spent plenty of time in Sacramento early this summer working out with his current teammates. He also made a trip to India with the NBA, where the Kings will play two games during the upcoming preseason.