NEW YORK — Major League Baseball appears headed to its shortest season since the 1870s.

Continuing a contentious back-and-forth in a bitter dispute over pay, baseball players told the commissioner's office on Saturday night that additional talks to start the season during the coronavirus pandemic are pointless and said owners should order a return to work.

The union's action might lead to a season of about 50 games rather than the 82 initially proposed by MLB. The Major League Baseball Players Association could respond by filing a grievance that would be heard by arbitrator Mark Irvings, arguing players are owed hundreds of millions of dollars in damages due to a shorter season.

Overall, this all could spark lengthy litigation over money and a renewal of the sport's labor wars. It could even prompt some star players to sit out.

"It unfortunately appears that further dialogue with the league would be futile," union head Tony Clark said in a statement. "It's time to get back to work. Tell us when and where."

MLB responded with a statement accusing the union of not negotiating in good faith and cited the March agreement that called for prorated salaries but did not obligate teams to play in empty ballparks. Clubs could file a grievance claiming the union did not meet its "good faith" obligation.

"The MLBPA's position that players are entitled to virtually all the revenue from a 2020 season played without fans is not fair to the thousands of other baseball employees that clubs and our office are supporting financially during this very difficult 2020 season," the commissioner's office said in a statement. "We will evaluate the union's refusal to adhere to the terms of the March agreement, and after consulting with ownership, determine the best course to bring baseball back to our fans."

While the  NBA, NHL and MLS have figured out deals to return in this summer of the coronavirus, baseball has descended into the fractious labor strife that led to eight work stoppages from 1972-95. The union has seethed followed a collective bargaining agreement in late 2016 that led to relatively flat salaries for five straight years, an unsuccessful grievance accusing the Chicago Cubs of manipulating third baseman Kris Bryant's service time  to delay his eligibility for free agency and a grievance accusing teams of improperly using revenue sharing proceeds, a process the union calls "tanking."

These raw negotiations heighten the chance of a spring training lockout after the current collective bargaining agreement expires on Dec. 1, 2021.

"Given your continued insistence on hundreds of millions of dollars of additional pay reductions, we assume these negotiations are at an end," union chief negotiator Bruce Meyer wrote in a letter to Deputy Commissioner Dan Halem on Saturday that was obtained by The Associated Press. "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. It is unfair to leave players and the fans hanging at this point, and further delay risks compromising health and safety. We demand that you inform us of your plans by close of business on Monday."

Players and MLB agreed to a deal on March 26 calling for prorated salaries, $170 million in salary advances and a guarantee of service time for 2020 even if no games are played. 

That deal agreement gave baseball Commissioner Rob Manfred the right to start the season provided there were no travel restrictions and games could be played before fans in regular-season ballparks. It called for "good faith" negotiations to play in empty ballparks or neutral sites.

Players insist they should not have to accept additional cuts. A unilateral decision to start play could mean the playoffs would remain at 10 teams and not expand to 16, as both sides have proposed. High-risk players can opt out and still receive salary and service, but others who sit out would lose both. 

"The solidarity of the players has never been more concentrated in years," said Scott Boras, baseball's most high-profile agent, who has three clients on the union's eight-man executive subcommittee.

MLB made three economic offers, the last Friday, and the union proposed two. The executive subcommittee held a call Saturday followed by a larger group of about 100 players, including the full executive committee and others. 

The sides remain far apart on how much players should get of the $4 billion in salaries they originally were set to earn: MLB has offered to guarantee $1.27 billion and increase the total to $1.45 billion if the postseason is completed. Players want $2.25 billion and an 89-game season.

"Players want to play. It's who we are and what we do," Clark said. "Since March, the association has made it clear that our No. 1 focus is playing the fullest season possible, as soon as possible, as safely as possible. Players agreed to billions in monetary concessions as a means to that end, and in the face of repeated media leaks and misdirection we made additional proposals to inject new revenues into the industry — proposals that would benefit the owners, players, broadcast partners, and fans alike. It's now become apparent that these efforts have fallen upon deaf ears."

Manfred said last week there is a "100%" chance of a season, adding "unequivocally we are going to play Major League Baseball this year." Yet, it will be the shortest season in more than a century. And Meyer's letter to Halem cited remaining open issues in the health protocols needed before players report for a resumption of training.

Owners must now decide whether to go ahead with a shortened schedule, of perhaps 48 or 50 games. A 50-game regular season at prorated salaries would total $1.23 billion, leaving the union to claim about $1 billion plus interest in damages should the case continue to a decision and players prevail.