JUPITER, Fla. — On the cusp of the lockout inflicting real consequences on the 2022 season, Major League Baseball and the MLB Players Association made enough progress toward a new collective bargaining agreement in a marathon day of negotiations to forestall the threatened postponement of opening day — at least for another 15 hours.

Monday was the deadline MLB had set for the 2022 season to begin on time. Both publicly and privately, the league has said it would begin canceling games if a deal was not done by the end of February — a date they arrived at by working backward from a March 31 scheduled opening day with a four-week spring training.

But on the eighth straight day of in-person negotiations, which stretched more than 16 hours, ending just before 3 a.m., the league pushed the deadline to Tuesday at 5 p.m. ET.

“We made progress and want to exhaust every possibility to get a deal,” a league spokesman said by way of explanation.

Commissioner Rob Manfred participated in several meetings between the two sides over the course of the marathon day. The first of those, in which Manfred and MLB’s lead negotiator Dan Halem met with MLBPA executive director Tony Clark and lead negotiator Bruce Meyer, was the union’s first indication that the league was serious about getting a deal done.

After three months of an owner-implemented lockout and seven days of consistent but unproductive negotiations in Florida, the two sides achieved by far the most visible progress with their backs up against a supposed wall. And what had looked like a long shot as recently as Sunday night became increasingly promising as the talks stretched deep into the night.

Eventually the union felt it had accomplished all it could without breaking to take stock and discuss the key issues with board members. And despite the league’s implicit optimism in extending the deadline, players still believed they were far apart on economics and that none of the major issues were fully resolved.

The eventual deal will be built on deeply interconnected elements, with the core economics representing the major scaffolding. At this point in bargaining everything is a package — concessions in one area are predicated on gains elsewhere — and everything is contingent on the careful balance being maintained.

Which is to say, nothing is really done until everything is done.

But a possible picture emerged by the time both sides broke to try to get some sleep.

The league’s offer includes a luxury tax threshold that starts at $220 million in 2022 and goes up to $230 million by the end of the CBA’s term, tax rates would remain the same as they were in the prior agreement — a significant shift from MLB’s original attempt to more than double the penalties and harden the de facto soft cap.

MLB offered a minimum salary that starts at $675,000 and increases each year by $10,000 and a bonus pool for pre-arbitration players of $25 million.

The league would concede its desire for a 14-team postseason, acquiescing to the union’s 12-team counter. But the union would drop its request to expand arbitration for players with two-plus years of service time beyond the current 22%.

All of which is contingent on the rest.

The union, which has resisted the implication that the season couldn’t be played in full even if the talks dragged on into March, would like to see those numbers higher across the board.

Players feel the league is trying to rush them into accepting a bad offer by creating artificial deadlines with financial implications. MLB has said that missed games will not be rescheduled and players will not be paid for those missed games. And in response, the union previously issued its own threats to reject an expanded postseason if the eventual deal didn’t include a full season of play or pay.

Those dual undesirable outcomes — and the broader mutually assured destruction of another disrupted season so soon after 2020 — were enough to motivate considerable movement Monday. The two sides will meet again at 11 a.m. ET on Tuesday for a final six-hour showdown to see if it’s enough to ensure an on-time opening day.