Let the negotiations begin.

With the calendar marching on and the window narrowing to salvage even half of the 2020 season, Major League Baseball owners agreed Monday to send an initial return-to-play proposal to the Players Association, a source confirmed. Talks between the league and the union will begin this week, likely as soon as Tuesday.

Details of the proposed plan haven’t been widely discussed, but according to multiple reports, it likely involves an 82-game schedule in regular-season markets starting in early July, 30-man rosters (expanded from 26), a taxi squad of additional players, and a universal designated hitter, according to the New York Post. Teams would play only within their respective divisions and against regional opponents in the other league. The Phillies, for example, could face the AL East’s New York Yankees, Tampa Bay Rays, Boston Red Sox, Toronto Blue Jays, and Baltimore Orioles in addition to their NL East rivals.

Two considerable hurdles — they might actually be more like mountains — must be overcome: health/safety concerns related to the epidemiology track of COVID-19, and player pay.

The latter is complicated due to the level of distrust that exists between the owners and players. But at least it’s within MLB’s control, unlike the unpredictable path of the virus and the availability of testing and monitoring protocols.

The players' union believes the compensation issue was settled by a March 26 agreement in which players were guaranteed a prorated portion of their 2020 salaries based on the number of games played. Given the potential health risks associated with playing in the age of coronavirus, players reportedly won't budge on another pay cut.

Owners claim that the March 26 agreement was based on fans being able to attend games. Without ticket sales, luxury suites, parking, concessions, and other revenue streams derived from fan attendance, MLB teams will lose an average of 40% of their expected revenues from which they pay players.

MLB’s proposal reportedly includes a one-time provision that would establish player salaries based on a revenue-sharing arrangement between the owners and players. The players won’t go for such an idea, according to The Athletic, with the union contending that the system would be akin to a salary cap.

It's a thorny issue. But it's also difficult to fathom that the season would be flushed because billionaire owners and millionaire players couldn't settle their squabbles over money in an industry that grossed a record $10.7 billion in revenues in 2019.

The health and safety concerns aren't as straightforward.

Not only will MLB need to convince players that the protective measures will be taken to reduce the risk of getting sick, but the cities and states in which teams play must reopen to the point where gatherings of more than 100 people are permitted. Additionally, MLB will need to secure testing for players without diverting resources from the general populace.

Furthermore, MLB will need to enact protocols for dealing with potential positive tests from players, managers, coaches, and other support personnel, some of whom might have underlying health conditions that put them or their family members at greater risk.

If the virus abates across the country during the summer, there’s concern within the medical community that it could reemerge in the fall. Even in South Korea, which reduced its new cases to single-digit totals for most of last week, the reported number of new cases rose to 34 on Saturday and 35 on Sunday.

In a lengthy and thoughtful Twitter thread shortly after news broke about the owners’ approval of the initial proposal, Washington Nationals reliever Sean Doolittle — a Shawnee High product whose wife, Eireann Dolan, has a history of respiratory issues — posed several questions related to the frequency and availability of testing.

Doolittle also wondered about modifications to clubhouses to prevent the spread of the virus and additional health-care benefits for players, staff, and other essential workers “to mitigate the unknown risks of putting on a baseball season during a pandemic.”

“Hopefully these concerns will be addressed in MLB’s proposal, first and foremost: 1) what’s the plan to ethically acquire enough tests? 2) what’s the protocol if a player, staff member, or worker contracts the virus?” Doolittle wrote. “We want to play. And we want everyone to stay safe.”

It’s all on the table now, up for discussion between the league and the players in a volley that could last for the next few weeks and, if all goes well, end with a resumption of spring training in early June.