Optimism is waning after four consecutive days of negotiations between NFL owners and players and was described as trending "backwards," player sources told ESPN.
Player sources said owners have reneged on a simplified formula that would have given players 48 percent of all revenue.
Player sources reaffirmed a setback in talks occurred when owners last week went "retro" on the formula that will divide the estimated $9.3 billion in annual revenue. The players believed the two sides had reached an understanding on a simplified formula in which they would receive 48 percent of revenue. Sources say owners reintroduced their previous formula by asking for $400 million to $500 million in expenses as credit off the top.
Players calculate that under the owners' proposal, it would leave them with approximately with a 45 percent take on revenue, an "unacceptable" amount that one player source said "sets us back to March 11 ... before the lockout."
A management source said the owners have not reneged on any revenue split, claiming "it's a negotiation, which is always subject to change."
A league source said the owners were more flexible Thursday afternoon on the revenue-split formula and maintained the theme of "negotiations are negotiations."
Player sources contend the owners' terms changed when the two sides convened a day after owners met June 21 in Chicago. A source said the players went into Thursday's negotiating session with owners at the table, hoping to "get them back on track. They wouldn't move. It's disappointing."
The two sides ordered in a late dinner and continued to meet Thursday night for more than 15 hours.
NFLPA chief DeMaurice Smith and members of the players' negotiating team were back for more talks Friday morning, which began at 9 a.m. ET, about six hours after they ended their last session.
U.S. Magistrate Judge Arthur Boylan is overseeing the process.
Smith was seen entering
a Minneapolis law firm where talks are being held shortly before the planned start of the latest discussions. Staffers and players, including Saturday and Brian Waters of the Kansas City Chiefs, joined him.
NFL commissioner Roger Goodell and Smith were joined Thursday by Boylan and a handful of owners -- John Mara of the New York Giants, Clark Hunt of the Chiefs, Jerry Jones of the Dallas Cowboys and Robert Kraft of the New England Patriots -- and players including Saturday, Waters and Domonique Foxworth of the Baltimore Ravens.
The latest round of negotiations between the two sides -- the fifth since they began hopping from city to city for meetings -- kicked off Tuesday with Goodell, Smith, their attorneys and staffs.
This location is significant because Minneapolis is where the players have filed a still-pending federal antitrust suit against the owners. The two sides met here for six days of court-ordered mediation under Boylan in April and May.
The July 4 holiday weekend has been floated by some members of their respective parties as a rough target for a deal, and that time has nearly arrived.
Owners and players are seeking a deal that would divide revenues for the $9 billion business -- the biggest hurdle to clear -- and guide league activities for years to come.
The lockout began March 12. Training camps are scheduled to open in three weeks, with the preseason-opening Hall of Fame game on Aug. 7.
Because players don't get their usual paychecks until the regular season, and revenue for the league revolves heavily around Sunday games, the financial urgency arguably hasn't arrived.
Rookies need to start learning their playbooks, though, and teams need free agency to arrange their rosters. Plus, an 8th U.S. Circuit Court of Appeals panel is still weighing a final decision on the legality of the lockout.
Chris Mortensen is ESPN's senior NFL analyst. Information from The Associated Press was used in this report.