The Major League Baseball Players Association asked MLB to set a schedule for the 2020 season rather than counter the latest return-to-play proposal by the league, setting the stage for MLB to implement a significantly shortened schedule and deepening the labor strife between the parties.

In a statement Saturday night, MLBPA executive director Tony Clark rejected MLB's latest proposal and said: "Further dialogue with the league would be futile. It's time to get back to work. Tell us when and where."

Major League Baseball Players Association Executive Director Tony Clark today released the following statement: pic.twitter.com/d1p3Oj4K70

— MLBPA Communications (@MLBPA_News) June 13, 2020

A March agreement between the parties allows MLB to set a schedule, and the league has suggested that in the absence of a negotiated agreement with the union it could impose a schedule of somewhere in the neighborhood of 50 games and pay players full prorated salaries worth a total of around $1.25 billion.

MLBPA lead negotiator Bruce Meyer, in a letter sent to deputy commissioner Dan Halem on Saturday night and obtained by ESPN, said: "We demand that you inform us of your plans by close of business on Monday, June 15."

In a statement on Saturday night, MLB said in part: "We are disappointed that the MLBPA has chosen not to negotiate in good faith over resumption of play after MLB has made three successive proposals that would provide players, Clubs and our fans with an amicable resolution to a very difficult situation caused by the COVID-19 pandemic."

Upon any implementation of a schedule, players wouldn't necessarily report to a second spring training immediately, sources told ESPN. The parties still do not have an agreement on a health-and-safety protocol and would need one before players arrive. Any season would be scheduled to start after a three-week spring training, though a coronavirus outbreak could change the league's plans. Multiple players on 40-man rosters have tested positive for the virus recently, according to sources.

If MLB does implement a season, both parties could file grievances to be heard by an arbitrator, though neither would necessarily delay games being played, sources said. The union could file a grievance that the league did not fulfill its obligation to play the most games possible, sources told ESPN. The March agreement says the league should use "best efforts to play as many games as possible, while taking into account player safety and health, rescheduling needs, competitive considerations, stadium availability, and the economic feasibility of various alternatives." The league could likewise file a grievance over a lack of good faith negotiations regarding salary by the union, sources said.

Commissioner Rob Manfred told ESPN this week that "unequivocally we are going to play Major League Baseball this year," placing the chances at "100 percent."

MLB has said it will lose billions of dollars this season and even more if it plays without fans in the stands, leading to it asking players to take a cut off the prorated portion of their salaries. The union has sought financial information to validate the league's projections and has said the documentation provided by the league has not sufficiently backed up the numbers. The union has held firm at full pro rata pay, citing the March agreement. MLB interprets the agreement differently, believing that the language in it allows for a negotiation on pay if games are played with no fans in the stands.

The league's last proposal to the players offered 72 games with 70% of their full prorated pay guaranteed and up to 83% following the completion of the postseason. The total of $1.5 billion was the highest offered by MLB, but it still fell well short of the full rate players are seeking after losing salary for the games thus far missed.

"Given your continued insistence on hundreds of millions of dollars of additional pay reductions, we assume these negotiations are at an end," Meyer said in the letter. "If it is your intention to unilaterally impose a season, we again request that you inform us and our members of how many games you intend to play and when and where players should report."

The league has been consistent in its insistence that the regular season end Sept. 27, citing health concerns as well as the desire of national TV partners not to have games extend into November, when the presidential election and football games will dominate the television landscape. The union's last proposal of 89 games would have had the regular season end in mid-October.

"Your refusal to play games in October is purportedly based primarily on concern for player health," Meyer wrote. "We believe this is a pretext. ... Other leagues are planning on playing in October and November, and we have proposed having the flexibility to play games at neutral sites if necessary to address any safety concerns. We believe your position is part and parcel of your general bad faith determination to play as few games as possible to punish players for refusing to capitulate to MLB's demands for massive pay cuts."

The fight over money has been at the center of the discussions between the parties, which included five proposals that did little to bridge the gap. The league increased the percentages of salary players would receive in each of its three proposals but decreased the number of games played, while the union started at 114 games of full pro rata and landed on 89 before declining to counter.

The union continued to call for more documents regarding MLB's financials, citing a report that the league had agreed to an extension of its national TV deal with Turner Sports that will bump the annual revenue from $350 million to the $500 million range.

"We ask again," Meyer wrote, "that you provide us with details on this and other negotiations."

Meyer, in his letter, called MLB's negotiation stance "one delay tactic after another."

The union's maneuver Saturday night could resolve that, end the back-and-forth and finally answer the question hanging over the sport for three months: When will baseball actually return?