The NFL Players Association will hold a meeting of player representatives and its executive committee Thursday in Los Angeles, sources told ESPN.

One source said it's unlikely there will be a vote Thursday on the owners' current proposal on the collective bargaining agreement, as the opposition among players to an expanded, 17-game regular season is currently too strong.

The league has given the players a "rough deadline" of the start of the 2020 league year (March 18) to work out a new deal. If no deal is in place by then, negotiations are likely to be tabled indefinitely, sources said. The current CBA is set to expire in March 2021.

Sources said the new CBA, as proposed by the owners, would be a 10-year deal and would raise the players' share of league revenue from 47% to 48.5%, with the possibility to go higher if and when the owners expand the regular season to 17 games. The earliest the league would begin a 17-game schedule would be 2021. The proposed deal would give the owners a three-year window from 2021-23 to execute their option to expand the season.

At this point, one source said, players don't believe the new deal includes enough health and safety improvements to justify an expansion of the season to 17 games. Players such as Russell Okung and Richard Sherman, who are expected to be present at Thursday's meeting, have publicly voiced their concerns about the effects an extra regular-season game would have on players' health and safety.

The 17-game schedule was first formally proposed to players during meetings held during Super Bowl week in Miami, sources said, and it was met with near-unanimous disapproval by players. . Sources also told ESPN's Brooke Pryor the funding rule has come up in discussions, -- a longstanding rule that keeps teams from giving players fully guaranteed contracts or fully paying out contracts.

The new proposal, one source estimated, would mean an extra $5 billion in revenue to the players over the life of the deal. It also would include changes to the league's drug policy (punishments to players who test positive for marijuana would be nearly eliminated) and discipline policy (modified significantly in the players' favor), improvements to player benefits (current and former), higher minimum cash spending floors for the teams and some structural changes to rules involving the franchise tag and the fifth-year option for first-round draft picks.

One of the key concessions the players won in the 2011 negotiations was a reduction in offseason practice time, and they are pushing for more such reductions in the next deal. Discussion has centered around training camp, where the players would like to see rules imposed that reduce contact and the amount of time teams can require them to be on the field. According to sources, the concessions the owners have offered on that front have not been sufficient for the players to concede on the expanded season.

The new deal also would allow owners to expand the annual field of playoff teams from 12 to 14.

Any expansion of the season would come with a commensurate reduction in the number of preseason games.

The NFLPA requires two-thirds of its 32 player representatives to approve a proposal before it moves ahead to the next stage, which is a vote of all players in the league. If it reaches that point, only a simple majority of the league's players would have to approve the deal. Two-thirds of the owners must then approve the proposal before it can be ratified.