SACRAMENTO, Calif. - California Gov. Gavin Newsom signed a bill Monday that would allow California athletes to earn money from the use of their names, images and likenesses, despite warnings from the National Collegiate Athletic Association that the measure would upend amateur sports.

Senate Bill 206 by Sen. Nancy Skinner (D-Berkeley) garnered national attention, with athletes including NBA stars LeBron James and Draymond Green lauding the California effort to give college athletes a share of the windfall they help create for their universities and NCAA. The bill passed the state Legislature unanimously.

Newsom, who played baseball at Santa Clara University, said in September that having been a student athlete, he had "very strong opinions on this subject."

The bill would prohibit the NCAA from barring a university from competition if its athletes are compensated for the use of their name, image or likeness beginning in 2023. NCAA rules strictly prohibit athletes from profiting in any way from their sports.

While the bill would allow athletes to sign endorsement deals with major companies, it would also open up smaller opportunities that were previously prohibited, such as paid youth coaching positions. SB 206 would still forbid schools from directly paying athletes.

The NCAA sent a letter to Newsom in September while lawmakers were mulling the bill, calling it "unconstitutional" and a "scheme." The letter was signed by NCAA President Mark Emmert and 21 other members of the organization's board of governors. The NCAA urged California to hold off on the bill to give a working group formed earlier this year more time to examine the name, image and likeness issue.

"Right now, nearly half a million student-athletes in all 50 states compete under the same rules," the letter read. "This bill would remove that essential element of fairness and equal treatment that forms the bedrock of college sports."

Skinner disputed assertions in the NCAA's letter, saying the sports association has resorted to threats because legal scholars have concluded her bill is on solid ground. Skinner said she hoped other states would pass similar legislation. Lawmakers in a handful of states have introduced bills challenging the NCAA's rules related to athlete pay.

In September, a New York state senator introduced legislation similar to Skinner's bill with the added provision that college athletic departments share 15% of annual revenue from ticket sales with student athletes.