COLLEGE PARK, Ga. - The country's most popular sport is in limbo for at least another day.

NFL owners overwhelmingly approved a tentative agreement Thursday to end the lockout, provided players re-establish their union and sign off on the deal. The players, however, didn't vote, saying they had not seen the full proposal.

Owners voted 31-0 - the Oakland Raiders abstained - and soon afterward, the league issued a press release announcing: "NFL clubs approved today the terms of a comprehensive settlement of litigation and a new 10-year collective bargaining agreement with the NFL Players Association."

Then NFLPA head DeMaurice Smith sent an email to team reps saying: "Issues that need to be collectively bargained remain open; other issues, such as workers' compensation, economic issues and end of deal terms, remain unresolved. There is no agreement between the NFL and the players at this time."

Players held a conference call Thursday night and decided not to vote.

Commissioner Roger Goodell spoke on the phone several times Thursday with Smith, including filling him in on the results of the vote before it was announced.

"Hopefully, we can all work quickly, expeditiously, to get this agreement done," Goodell said at a news conference at an Atlanta-area hotel. "It is time to get back to football. That's what everybody here wants to do."

But several players took to Twitter, expressing opposition to the proposal. Pittsburgh Steelers safety Ryan Clark wrote: "The owners want u to believe that they have been extremely fair everywhere and this is their 'olive branch' to finalize it."

The four-month lockout is the NFL's first work stoppage since 1987. And as a result, this season's exhibition opener was canceled Thursday - the Aug. 7 Hall of Fame game between Chicago and St. Louis in Canton, Ohio.

"The time was just too short," Goodell said. "Unfortunately, we're not going to be able to play the game this year."

Providing players eventually approve the agreement, team facilities would open Saturday, and the new league year would begin Wednesday.

Owners exercised an opt-out clause in the old collective bargaining agreement in 2008, setting the stage for the recent labor impasse. The new deal does not contain an opt-out clause.

"I can't say we got everything we wanted to get in the deal," New York Giants owner John Mara said. "I'm sure (players) would say the same thing. ... The best thing about it is our fans don't have to hear about labor-management relations for another 10 years."

Thursday's owners meeting near Atlanta's airport lasted nine hours - including breaks for lunch and dinner. Black limousines that lined up outside at midafternoon wound up waiting and waiting for owners to emerge. More than 100 members of the media packed into the lobby and lined the hallways leading to the conference room where the owners met behind closed doors.

After word of the owners' vote emerged, one fan at the hotel, Dave Gower of Knoxville, Tenn., said: "Finally. I don't understand why it took so long. I hope the players take it and run with it."

The old CBA expired March 11, when federally mediated negotiations fell apart, and the owners locked out the players hours later. Since then, teams have not been allowed to communicate with current NFL players; players - including those drafted in April - could not be signed; and teams did not pay for players' health insurance.

The basic framework for the league's new economic model - including how to split more than $9 billion in annual revenues - was set up during negotiations last week.

"These things, by their very nature, aren't supposed to make you necessarily happy when you walk out the door. It was a negotiation," Cowboys owner Jerry Jones said. "I don't mean to sound negative, but it isn't exactly like Christmas has come along here."

Final issues involved how to set aside three pending court cases, including the antitrust lawsuit filed against the NFL in federal court in Minnesota by Tom Brady and nine other players. NFL general counsel Jeff Pash said the owners' understanding is that case will be dismissed.

One thing owners originally sought and won't get, at least right away, is expanding the regular season from 16 games to 18. That won't change before 2013, and the players must agree to a switch.

"We heard the players loud and clear. They pushed back pretty hard on that issue," said Atlanta Falcons president Rich McKay, chairman of the league's competition committee.

Goodell also announced that owners approved a supplemental revenue-sharing system, something Smith noted in his email to team reps. "Obviously, we have not been a part of those discussions," he wrote.

Even after all acceptable terms are established, a deal would lead to a new CBA only if NFLPA team reps recommend re-establishing the group as a union, which must be approved by a majority vote of the 1,900 players.

In March, when talks broke down and the old CBA expired, the NFLPA said it was dissolving itself as a union and instead becoming a trade association, a move that allowed the players to sue the league under antitrust law. But only a union can sign off on a CBA.

"We think we have a fair, balanced agreement," Panthers owner Jerry Richardson said.

The deal would make significant changes in offseason workout schedules, reducing team programs by five weeks and cutting organized team activities (OTAs) from 14 to 10 sessions. There will be limited on-field practice time and contact, and more days off for players.

Current players would be able to stay in the medical plan for life. They also will have an injury protection benefit of up to $1 million of a player's salary for the year after his injury and up to $500,000 in the second year after his injury.

A total of $50 million per year will go into a joint fund for medical research, health-care programs, and charities.

If the players approve the deal, the NFL would go back to the business of football pretty quickly:

-On Saturday, teams can stage voluntary workouts at club facilities, and players may be waived. Contracts can be re-negotiated and clubs can sign draft picks and their own free agents. Teams can also negotiate with, but not sign, free agents from other clubs and undrafted rookies.

-On Sunday, teams can sign undrafted rookies.

-On Wednesday, the league year officially begins, so free agency opens in full, and all training camps will open with a 90-man roster limit; activities that day will be limited to physicals, meetings and conditioning. All clubs must be under the salary cap.

-Players can practice without pads next Thursday and Friday.