(BCSNN) — The Big 12 has unanimously voted to ban professional athletes from returning to college competition in all sports, the conference announced Wednesday night — becoming the first league to implement a blanket prohibition across its entire athletic portfolio.

The move aligns the Big 12 with the Big Ten and SEC, both of which announced similar bans Tuesday. The ACC is also trending toward adopting comparable restrictions, sources told ESPN’s Pete Thamel, signaling a nationwide shift toward tightening eligibility rules amid mounting legal challenges.

Under the Big 12’s policy, athletes who declared for a professional draft and did not withdraw, those listed on a professional roster, or anyone who has signed a contract with a professional league will be barred from returning to college competition.

The decision arrives during a turbulent stretch for the NCAA, sparked by court rulings that have allowed athletes from the 2022 recruiting class to pursue a fifth season of eligibility. That group includes former Ole Miss standouts Dae’Quan Wright and Zxavian Harris, who left their NFL teams — the Cleveland Browns and New Orleans Saints — with plans to join Lane Kiffin’s roster at LSU.

Wright and Harris, who played four college seasons before going pro, believed they had exhausted their eligibility. But a recent court order opened the door for them and dozens of others to return, creating widespread uncertainty across college athletics.

The NCAA’s new age‑based eligibility model, adopted in June, grants athletes five seasons of competition within five years, but does not take effect until next season. Crucially, it does not apply retroactively to players who began their careers in 2022–23, leaving them in a gray area that has fueled lawsuits and emergency restraining orders.

The Big 12’s decision reflects a growing desire among conferences to restore clarity and consistency — even as legal battles continue to reshape the boundaries of college eligibility.