MINNEAPOLIS — NFL Commissioner Roger Goodell and NFLPA head DeMaurice Smith ended a 15-hour bargaining session early Friday, barely breaking for a quick nap before resuming in the morning.

U.S. Magistrate Judge Arthur Boylan, who is overseeing the process, said the sides will resume negotiations at 8 a.m.

The latest talks come as the NBA began its own lockout after it failed to reach a new collective bargaining agreement with its players. It is believed to be only the second time that two leagues have been shut down simultaneously by labor problems. The NHL and MLB were idle from October 1994 through mid-January 1995.

The negotiations in Minneapolis are aimed at ending the NFL’s longest work stoppage ever and began on Tuesday, with just Goodell, Smith, their attorneys and staffs. The leaders of the two sides left the table to address incoming rookies an orientation symposium in Florida on Wednesday morning and then flew back to Minnesota.

Sitting down with Boylan at a Minneapolis law firm were a handful of owners — John Mara of the New York Giants, Clark Hunt of the Kansas City Chiefs, Jerry Jones of the Dallas Cowboys and Robert Kraft of the New England Patriots — and players including Jeff Saturday of the Indianapolis Colts, Brian Waters of the Kansas City Chiefs and Domonique Foxworth of the Ravens.

John Hancock Jr., a labor law expert in Detroit for the firm Butzel Long who has closely followed the NFL situation, said he believes an agreement could be reached soon, perhaps early next week. He said one sign of progress was the smaller Tuesday meeting and the lack of details and updates being shared.

The recent cordiality between Smith and Goodell prompted speculation about where the talks stood.