The Browns, who will play the Oakland Raiders, haven't been blacked out since the franchise returned to Cleveland in 1999. A Browns spokesman said the league has given the team until 1 p.m. ET Saturday to sell the remaining tickets or the game will not be shown within a 75-mile radius of Cleveland.
The Browns (3-11) haven't had a blackout since the final game of 1995, their last before former owner Art Modell moved his franchise to Baltimore. Previously, the Browns combined with local stations to buy remaining tickets and distributed them to charities and area businesses.
The Associated Press contributed to this report.