When Major League Baseball and its players’ union reached agreement on a modified economic deal last month — completing it on the very day the season was supposed to have begun — it was taken as a sign of goodwill between sides that are typically at odds and a statement of shared purpose as the sport plotted a way forward through the novel coronavirus pandemic.

But now that goodwill is in danger of being squandered over the issue of how players should be paid for games without fans. And even as the sport navigates massive hurdles in its quest to start the 2020 season — which would almost certainly be played at neutral sites in empty stadiums, at least in the early stages — the widening rift with the union presents another, unforeseen one with the power to scuttle the entire plan.

At the heart of the issue is a dispute over what was agreed to in March. The union believes the matter of player compensation was settled: Per the agreement, players would receive prorated portions of their salaries based on how many games are played (or $170 million in the event the entire season is wiped out).

“Players recently reached an agreement with [MLB] that outlines economic terms for resumption of play, which included significant salary adjustments and a number of other compromises. That negotiation is over,” Major League Baseball Players Association chief Tony Clark said in a statement Tuesday. “We’re now focused on discussing ways to get back on the field under conditions that prioritize the health and well-being of players and their families, coaches, umpires, team staff and fans.”

However, MLB views the March agreement as pertaining specifically to games with fans, and that games without fans — minus the lost revenue from ticket sales and concessions — would require compensatory adjustments in the players’ salaries.

“In the agreement reached earlier this spring, the commissioner’s office and the MLBPA agreed that the season would not commence until normal operations — including fans in our home stadiums — were possible,” Deputy Commissioner Dan Halem said in a statement. “If circumstances require, we will, consistent with our agreement with the union, negotiate in good faith over a framework to resume play without fans that is economically feasible for the sport.”

Halem’s statement, perhaps not coincidentally, uses language similar to what’s contained in the agreement, particularly a stipulation that says the sides “would discuss in good faith the economic feasibility of playing games in the absence of spectators or at appropriate substitute sites.”

MLB has estimated around 40 percent of its operating revenue comes from ticket sales and related on-location, game-day purchases, and some teams could begin furloughing, laying off or reducing the salaries of certain employees beginning May 1.

Without additional salary relief from players, MLB could argue it would lose money by playing games without fans. But the union points out there would also be cost savings from games without fans — without the need to pay ushers, concessionaires and other stadium workers, for example — and that the lost revenue could be recouped from a full or expanded postseason.

The rift appears to have been revealed accidentally last week when New York Gov. Andrew M. Cuomo (D), describing on CNN a conversation he had with New York Mets chief operating officer Jeff Wilpon, said: “Apparently, [MLB] would have to make a [new] deal with the players, because if you have no one in the stands, then the numbers are going to change, right? The economics are going to change.”

The sides are unlikely to discuss the salary dispute any time soon — or any specific conditions for the resumption of play — because any such talks would require significant progress toward a plan for starting the season, a notion that remains muddled by factors outside MLB’s control.

Although MLB has looked into opening its season in Arizona without fans — using the Diamondbacks’ Chase Field and 10 spring training facilities, and with players and essential personnel sequestered in a protective bubble of self-isolation and frequent testing — significant roadblocks remain, particularly in regards to the number of new coronavirus cases and the availability of testing, before that becomes a legitimate possibility.

Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases, is among those who have endorsed the idea of baseball resuming this summer without fans if the virus is under control and testing is widely available, so as not to divert necessary resources from the general public. MLB has made clear it won’t move forward until it receives assurances from government and public health officials that it is safe to do so.

“I think we all need … to wait for the situation to unfold more, [with] more information, and then make realistic decisions on what’s possible,” Commissioner Rob Manfred said in an interview with the Associated Press. “The threshold question is the health question, and that’s where we’re spending the most time.”

But players clearly believe the “Arizona plan” — or alternate ones that could also include sites in other states — would already require significant sacrifices for them, including an inherent risk to their health and a willingness to be isolated apart from their families for months at a time.

Three-time American League MVP Mike Trout, whose wife is due to deliver their first child this summer, and three-time National League Cy Young winner Clayton Kershaw, a father of three, are among the superstar players who have expressed skepticism at the feasibility of such a plan.

“There are a lot of red flags. There are a lot of questions,” Trout said last week on NBC Sports Network. “Obviously, we would have to agree on it as players. I think the mentality is that we want to get back as soon as we can. But it has to be realistic. It can’t be sitting in our hotel rooms and just going from the field to the hotel room and not being able to do anything. I think that’s pretty crazy.”

In such an atmosphere, it might be considered a welcome development — even a return to normalcy, in a sense — if MLB and the union begin bickering over salaries, because it would mean conditions had advanced to the point where they could start looking at concrete plans to start the season.

But should the whole enterprise be derailed by the most basic and timeless of arguments, a fight over money, it might also be considered an unpardonable sin.

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