Major League Baseball remained deadlocked with its players at the start of a critical week in efforts to launch the 2020 season. The owners made a new economic proposal Monday, the union indicated it would reject it, and as the impasse drags on, the default solution of a shortened season of around 50 games becomes more likely.

In its latest proposal, MLB pitched a 76-game regular season, with players earning up to 75 percent of their prorated salaries. MLB officials framed it as an attempt to find middle ground between the significant pay cuts the owners asked for in their initial proposal of an 82-game season — with the cuts made on a sliding scale that hit hardest players making the highest salaries — and the MLB Players Association’s consistent demands for full, prorated shares of 2020 salaries based on the number of games played.

The new proposal, first reported Monday morning by ESPN and confirmed by a person familiar with it, would guarantee players 50 percent of their prorated salaries across the board — dropping the sliding scale — and that figure would climb to 75 percent if the postseason is completed. The season would begin in mid-July, and the World Series would wrap up by the end of October; MLB fears a second wave of the novel coronavirus in the fall could wipe out its lucrative playoffs.

As part of the proposal, MLB called for a 16-team postseason — six more teams than the normal configuration and two more than in previous proposals — which could boost industry revenue, because a large chunk of MLB’s earnings come from its lucrative postseason television contracts.

The proposal also added an enticement that could improve players’ standing in free agency this offseason: It would eliminate the qualifying offer and draft-pick compensation for certain free agents, which theoretically would make teams less likely to avoid those players on the open market.

The union shot down the offer, and its leadership was mulling whether even to make a counterproposal. MLB asked the union to respond by Wednesday.

The sides agreed to the pro rata arrangement in a March 26 deal governing the sport’s shutdown, and the union considers player compensation to be settled. MLB believes it is entitled to further relief to account for diminished revenue as a result of the season being played in empty stadiums.

In some regards, the union considers MLB’s latest offer a step backward, because it guaranteed fewer overall dollars to players in 2020 and would shift some of the risk for a lost postseason from the owners to the players. The union also bristled at MLB’s insistence, contained in its new proposal, that players sign a waiver acknowledging the risk of playing amid the coronavirus pandemic, which the MLBPA took as an attempt to deny players the right to challenge MLB if they believe it failed to create a safe work environment.

Simultaneous to the economic negotiation, the sides have also been working to reach an agreement on health and safety protocols for the 2020 season.

In the absence of an economic deal, MLB has indicated it is prepared to implement a plan of around 50 regular season games at full prorated salaries, as the March agreement gives it the right to do — a reality that all but guarantees some form of a baseball season in 2020.

Though neither side finds 50 games to be a satisfying number for a representative season, each day that passes without a deal makes that scenario more likely. The union probably would respond by pulling its support for an expanded postseason — MLB’s right to dictate the season length applies only to the regular season — and could file a grievance challenging MLB’s actions.

Starting the season around July 4, as MLB originally had hoped, now seems all but impossible because pitchers would require a training camp of around three weeks to build up arm strength before the games begin.