PHILADELPHIA -- Lights dazzled at Citi Field the morning of Dec. 4, when the Mets, for the first time under general manager Brodie Van Wagenen’s stewardship, opened the ballpark's doors to crow about an offseason move. Dressed in a suit and a bright orange tie, Van Wagenen announced what the world already knew: that the Mets had acquired eight-time All-Star Robinson Canó and stud closer Edwin Díaz in a seven-player trade with the Mariners.

Of Cano, Van Wagenen said that morning: “He immediately will impact the middle of our lineup and increase the run production in a meaningful and significant way.”

Of Diaz, Van Wagenen boasted: “He will be the anchor of our bullpen and electrify our fan base.”

Now more than halfway into the first Mets season for both, neither vision has come to pass. Diaz blew his fourth save Thursday in spectacular fashion, allowing five runs in the ninth inning to send the Mets to a 6-3 walk-off loss to the Phillies at Citizens Bank Park. Cano struck out as a pinch-hitter, capping a 5-for-37 (.135) road trip that saw the Mets win just three of 11 games.

“It’s tough to swallow,” manager Mickey Callaway said.

• Box score

Callaway has said similar things throughout the Mets’ five-game losing streak, because each defeat has seemed so similar to the last. Thursday, New York received life when Todd Frazier hit a go-ahead two-run homer in the top of the ninth, but it frittered away a lead for the fifth consecutive game.

The rally began as so many do, with a leadoff walk. Diaz then coughed up a game-tying homer to Maikel Franco, throwing an 0-2 fastball over the heart of the plate. After a strikeout, a second walk and a single followed, before Diaz ran another two-strike heater toward the inner half of the plate -- this time to Jean Segura, who crushed it for a walk-off three-run homer.

“It seemed like they were prepared for every pitch,” said Diaz, whose 4.94 ERA is more than double his 1.96 mark from last season. “It was just a bad day for me.”

It was mostly a rest day for Cano, who chalked his slump up to hitting the ball “right at guys … with no luck.” The numbers disagree. Cano’s average exit velocity and expected slugging percentage are both roughly unchanged from May, and down significantly from last season, when a strong second half piqued Van Wagenen’s interest in his former client.

Barely a month after taking the job, the new GM made his first and boldest move, acquiring Cano and Diaz for prospects Jarred Kelenic, Justin Dunn and Gerson Bautista, and veterans Jay Bruce and Anthony Swarzak.

“I feel like I’m 25 right now,” Cano said the day the trade became official.

“I came here to win,” added Diaz.

Like most teams, the Mets’ history is fraught with regrettable trades -- a fact that will be on full display this weekend, when the 1969 World Series champions gather for a 50th anniversary celebration at Citi Field. Two years after winning, the Mets dealt a complementary piece from that team, Nolan Ryan, to the Angels for Jim Fregosi, who accomplished little in Flushing. Six years after that, they dealt Tom Seaver -- nicknamed “The Franchise” due to his importance in Mets history -- to the Reds in a five-player deal that shook their foundations.

It is way, way too early to compare Van Wagenen’s first trade to those. Kelenic (ranked No. 24 by MLB Pipeline) looks sensational now as one of baseball’s best prospects, but he has yet to see a pitch above Class A ball. Scouts have never profiled Dunn as a front-line starter. Bautista has struggled with injuries and ineffectiveness. Bruce and Swarzak, for all their successes with the Phillies and Braves, respectively, would not have been long-term assets in New York. And the trade could have even been worse; early iterations had potential All-Star Jeff McNeil involved, before the Mets removed him from consideration.

Consider that a minor solace. Despite Van Wagenen’s advertisement of the deal as an avenue to “win now” and “win in the future,” this trade was always mostly about the present. In Diaz, the Mets bought high on what they believed was baseball’s best closer. In Cano, they paid for potential strong seasons on the front end, knowing the final two or three years of his contract -- it doesn’t expire until Cano is 40 years old -- were bound to be ugly.

To receive roughly replacement-level value from those two combined in 2019, when they were supposed to be at their strongest, is troubling for a Mets team wedded to both for years.

“Not right now,” Callaway said when asked if he could have envisioned the trade turning out this way. “But I have faith in those guys. Cano’s starting to come around with the bat it seems like the last couple of days. … Diaz, his last couple of outings, has looked electric. And then this happens. Hey, they’ve got to bounce back.”