When the NFL and the players' union agreed to federal mediation, they knew it was voluntary.
In theory, either side could walk away at any time.
Instead, they keep coming back to the table, and the current round of negotiations appears set to stretch through Thursday — which would make for a full week.
One indication of how things are going: The union called off a meeting it was supposed to hold with player agents in Indianapolis on Thursday, citing the ongoing mediation. Instead, the NFL Players Association will host agents on Friday.
In the meantime, Commissioner Roger Goodell, NFL Players Association executive director DeMaurice Smith and members of their bargaining teams have met for a total of about 35 hours over five consecutive days, including about eight on Tuesday, at the Federal Mediation and Conciliation Service, a U.S. government agency.
Among those joining Smith on Tuesday were Chicago Bears linebacker Hunter Hillenmeyer, Baltimore Ravens cornerback Domonique Foxworth and former player Sean Morey.
All participants have been abiding by mediator George Cohen's request not to discuss the talks publicly.
"You guys will just speculate too much on whatever I say," Hillenmeyer said when he left.
Union spokesman George Atallah wrote in an e-mail to The Associated Press: "Every report about what's happening in the room at this point is pure speculation."
After months of infrequent and sometimes contentious bargaining, the league and union have been communicating face-to-face since Friday.
They agreed to try mediation in a bid to find common ground before the current labor deal expires at the end of the day March 3. The union has said it believes team owners want to lock out the players as soon as the next day, which could threaten the 2011 season.
One key member of the NFLPA negotiating team, outside counsel Jeffrey Kessler, walked out Tuesday with a rolling suitcase and got into a waiting taxi. He was leaving town ahead of Thursday's hearing in Minneapolis in front of U.S. District Court judge David Doty for the union's appeal of a ruling about whether the NFL improperly negotiated TV contracts. Doty holds jurisdiction over NFL labor matters.
"I've got to focus now on Minnesota," Kessler said.
The league and union went more than two months without any formal bargaining until Feb. 5, the day before the Super Bowl. The sides met again once the next week, then called off a second meeting that had been scheduled for the following day.
The most recent CBA was signed in 2006, but owners exercised an opt-out clause in 2008.
The biggest issue separating the sides is how to divide about $9 billion in annual revenues. Among the other significant points in negotiations: a rookie wage scale; the owners' push to expand the regular season from 16 games to 18 while reducing the preseason by two games; and benefits for retired players.
AP Sports Writer Joseph White contributed to this report.