Representatives of the NFL and its locked-out players concluded a series of undisclosed negotiating sessions in the Chicago area Thursday on the eve of a crucial court hearing on the nearly three-month old pro football shutdown.

The talks, which began Tuesday evening, included NFL Commissioner Roger Goodell, several prominent team owners, a handufl of players and DeMaurice Smith, executive director of the dissolved players’ union. The sessions are scheduled to conclude about mid-day Thursday, the sources said.

Among the owners reported to be in attendance for at least some of the meetings were the New England Patriots’ Robert Kraft, the New York Giants’ John Mara, the Dallas Cowboys’ Jerry Jones, the Carolina Panthers’ Jerry Richardson and the Pittsburgh Steelers’ Art Rooney II. The players’ group reportedly 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-ordered mediation sessions scheduled for next week in Minneapolis under Boylan’s direction were canceled Thursday by the court, which wrote that it was involved in confidential settlement discussions with the parties.

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. But it did appear that the two sides at least were attempting to establish a rapport and perhaps find some common ground for further negotiations. The talks — which the two sides did not disclose — were taken as a sign that a deal could be possible in time to preserve the 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. “The only way to maximize this is with a long-term deal. Any leverage gained through litigation is only short-term.”

Players have been locked out by the owners since March 12. They dissolved their union March 11 and filed an antitrust lawsuit against the owners.

Attorneys for the two sides are scheduled to argue about the legality of the lockout before a three-judge panel of the U.S. Court of Appeals for the Eighth Circuit at a hearing Friday in St. Louis. The judges will rule on the NFL’s appeal of the April 25 decision by U.S. District Judge Susan Richard Nelson to grant the players’ request for an injunction that halted the shutdown.

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 court later extended that stay until it issues a ruling.

Smith is scheduled to attend Friday’s hearing but Goodell is not scheduled to be there.