DeMaurice Smith, executive director of the NFL Players Association, met with NFL Commissioner Roger Goodell for secret talks in the Chicago area. (Jim Mone/Associated Press)

Representatives of the NFL and its locked-out players concluded two days of negotiations Thursday, a development that some in pro football saw as the first sign in weeks that the two sides are serious about ending their bitter labor standoff.

The talks, which were secret until disclosed by the media, began Tuesday evening in the Chicago area and included NFL Commissioner Roger Goodell and DeMaurice Smith, the executive director of the dissolved players’ union. They were taken by some as a signal that a deal could be possible in time to preserve the entire upcoming season.

“I’ve said all along that when the people who are negotiating this deal put the best interests of the game ahead of their own self-interests, it’s a good sign, because it means a resolution is possible,” veteran agent Peter Schaffer said Thursday.

Goodell was joined by several prominent owners, including the New England Patriots’ Robert Kraft and the New York Giants’ John Mara. Smith was accompanied by a group of players that included Kevin Mawae, the retired center who is the president of the dissolved union, and veterans Mike Vrabel and Jeff Saturday.

Chief Magistrate Judge Arthur J. Boylan, the Minneapolis-based mediator appointed by a federal judge, attended the meetings. The court later canceled mediation scheduled for next week in an order that said it was involved in confidential settlement discussions with both sides.

The league and players issued a joint written statement that said: “The parties met pursuant to court mediation. Owners and players were engaged in confidential discussions before Chief Magistrate Judge Boylan. The court has ordered continued confidentiality of the mediation sessions.”

It’s not clear if any formal bargaining took place in Chicago during the meetings, which occurred on the eve of a critical appellate court hearing Friday on the legality of the lockout. But it did appear that the two sides were attempting to establish a rapport and find common ground for further negotiations. Neither side disclosed the talks, which were first made public by the Chicago Tribune.

But their resumption reinforced the notion that the differences between the two sides aren’t insurmountable if a mutual willingness to complete an agreement exists.

“I don’t think there’s any question there’s a deal to be struck,” David Cornwell, an attorney who represents players in drug-related cases and other matters, said earlier this week.

When talks broke off in March, the two sides were about $10 million per team apart in their deliberations over annual salary cap figures—a divide of roughly $320 million league-wide in the first year of the proposed deal. The talks over money had evolved to salary-cap projections in the final stages before they broke down on March 11 and players were locked out March 12. The players dissolved the NFL Players Association and filed an anti-trust lawsuit against the owners and the league.

Originally, the league had demanded that additional money for annual expenses be set aside for owners before the players’ portion of revenues under the salary cap is calculated.

One point of contention when the talks collapsed in March was the players’ request for additional financial data about the teams. Another issue was what became known as a “true-up,” or how much the players would receive of future revenues that exceed annual projections.

“It boils down to: How are you going to share the excess?” Cornwell said.

Players said in March that an agreement never was close and Smith was critical at the time of the owners’ offer. The offer included a reduction in players’ offseason workouts, a provision that the sport would put off implementing a proposed 18-game regular season, and a guarantee that it never would extend the season without the players’ approval.

The league doesn’t want its labor situation subjected to ongoing oversight by a federal court, and has proposed having players blood-tested for human growth hormone.

Through spokesmen, both sides declined to comment about this week’s talks.

Some legal experts have said for months that serious negotiations would take place only after the battle for advantage played out in court for some length of time and the calendar dictated that a settlement was necessary to save a full season.

“There is always the search for leverage,” Goodell said at last week’s meeting of the owners in Indianapolis. “At some point that has to end, and you have to negotiate. That’s where we are.”

Attorneys for the two sides are scheduled to argue the legality of the lockout before a three-judge panel of the U.S. Court of Appeals for the Eighth Circuit at Friday’s hearing in St. Louis. Smith is scheduled to attend the hearing, while Goodell is not.

The judges will rule on the NFL’s appeal U.S. District Judge Susan Richard Nelson’s April 25 decision to grant the players’ request for an injunction that lifted the lockout. The league re-imposed the lockout April 29 after the appellate court granted the NFL’s request for a temporary stay of Nelson’s injunction. The appeals court later extended that stay until it issues its ruling.

Gabriel Feldman, director of the sports law program at Tulane University, said he expects the court to rule in two to six weeks. He called any further appeal by either side “a long shot” and said earlier this week: “We are looking at the step that will put in place the rules of engagement for. . . the negotiations.”

If the NFL loses its appeal and the lockout is lifted in court, it would be forced to reopen for business under not-yet-announced rules for free agency. But two of the judges wrote in granting the permanent stay that the league was likely to prevail in the appeal.

Feldman said this week that “things can change” but added that “unless something extraordinary happens, it’s more likely than not the lockout will remain in place” when the appeals court rules.

The players still have their antitrust case before Nelson, and the two sides are awaiting a ruling by U.S. District Judge David S. Doty on potential damages in a case involving the sport’s television contracts. The players are seeking more than $2.5 billion in compensatory and punitive damages and want Doty to deny the league access to approximately $4 billion in annual TV revenues if the lockout extends into the season.

The NFL also has asked the National Labor Relations Board to declare the players’ decision to dissolve their union nothing more than a bargaining tactic.

Dallas Cowboys owner Jerry Jones said last week that any deal between the league and the players “has to cover everything. If there are any dangling participles out here, then you don’t have an agreement.”

An agreement on how much future revenue beyond projections should go to the players would, for example, enable Smith to accept a deal that he previously criticized, some within the sport seem to believe. A deal also may need to settle all current litigation and address the league’s desire to avoid future court oversight of its labor situation, as well as its proposal to have players blood-tested for human growth hormone.

Some in the sport believe that Smith and other leaders on the players’ side would face increasing pressure from agents and players to complete a deal if the lockout remains in place as the season nears. But Cornwell said he thinks players still have leverage in talks, because the owners need labor peace to restore the sport’s prosperity.

The regular season is scheduled to begin Sept. 8. Teams normally would begin reporting to training camp by early August. There will have to be a period for teams to sign free agents and trade players, activities that have been on hold during the lockout.

“I think we really want that urgency because I think there’s real losses to be had if we start a training camp Sept. 1 and we play the first game Sept. 20,” Indianapolis Colts owner Jim Irsay said last week. “I mean, that’s really damaging. . . You’re trying to create that. . . environment where you really roll up your sleeves and get something done. I’m still hopeful that can happen.”