The New York Mets and Seattle Mariners were on the verge of a complex, fascinating, blockbuster trade Friday pivoting around eight-time all-star second baseman Robinson Cano — a proposed deal that gains at least one extra layer of intrigue from the fact the Mets' current general manager and the former agent who negotiated Cano's massive deal in Seattle five years ago are the same person.

By late Thursday, the outlines of the trade were reportedly settled: Cano, 36, would head to Queens with 24-year-old right-hander Edwin Diaz, the best young closer in the game, while the Mariners would receive veteran outfielder Jay Bruce, right-handed reliever Anthony Swarzak and several prospects. The Mariners would also be kicking in as much as half of the $120 million still owed to Cano over the next five seasons.

Some of the final pieces, including the amount of money changing hands, were still being negotiated Friday, according to multiple reports, with no official word expected until Saturday at the earliest. Among the prospects reportedly going to Seattle were outfielder Jarred Kelenic, the sixth-overall pick of the 2018 draft, and right-hander Justin Dunn, the 19th-overall pick in 2016.

For now, the Mets-Mariners trade has sucked all the oxygen out of an offseason marketplace that has been obsessed mostly with the potential landing spots for free agent sluggers Bryce Harper and Manny Machado.

Like Alex Rodriguez in 2004, Cano is apparently going to be traded in the middle of a landmark, 10-year contract. Cano's $240 million deal with the Mariners, tied for the third-largest in baseball history, was negotiated mostly by CAA's Brodie Van Wagenen, who left the agent business last month to accept the position of GM of the Mets — a much-scrutinized move that drew criticism from other agents and concern from baseball's union over real or perceived conflicts of interest.

But with the Mariners said to be desperate to rid themselves of Cano's contract — to the point of being willing to attach it to the more desirable (and inexpensive) Diaz — Van Wagenen and the Mets were a natural fit. Many in the industry, however, found the trade to be curious at best from the Mets' perspective, given Cano's age and contract status — and the lack of a designated hitter spot in the National League to cushion his expected defensive decline - not to mention the 80-game suspension he served in 2018 for a failed drug test.

In a more generous reading, the trade signals the Mets' intention to contend again in 2019 following consecutive fourth-place finishes in 2017 and 2018, and despite a newly competitive atmosphere in the National League East division — where the defending champion Atlanta Braves are still trending up, the Philadelphia Phillies have piles of money to spend this winter, and the Washington Nationals have finished first or second every year since 2012.

Diaz, who has a 100-mph fastball and saved 57 games in 2018, was the Mets' primary target — not to mention that of just about every contender upon finding out the Mariners were making him available — and he will make close to the major league minimum salary of $550,000 in 2019, with three additional years of club control.

But relievers are notoriously volatile as commodities, and an elite closer is an unnecessary luxury item for a team coming off a 77-85 season — unless that team believes it is positioned for a major leap forward. Even if that's the case, the Mets could have just as easily signed a veteran closer out of a well-stocked free agent market — Craig Kimbrel, Zach Britton, David Robertson and Andrew Miller among the available names — without taking on Cano's thorny presence or sacrificing top prospects.

The Mariners' strategy, on the other hand, is much more clear-cut. Should this trade go through, general manager Jerry Dipoto will have traded ace lefty James Paxton, catcher Mike Zunino, Cano and Diaz from a roster that won 89 games in 2018 and contended for a wild card well into August. But the Mariners clearly didn't see themselves as ready to take on the Houston Astros in the AL West and decided to focus longer-term by rebuilding what had been one of the game's worst farm systems.

Given the lengthy trajectories and alarming rate of attrition of baseball prospects, it could be years before anyone can say definitively which team made out better in the expected blockbuster.

But this much is true already: Both the tearing down of an 89-win Mariners team and the risk-averse restocking of a 77-win Mets team, while occupying opposite poles of the spectrum between tanking and going for it, are remarkably aggressive moves.