NEW YORK -- When the Mets optioned 21-year-old catching prospect Francisco Álvarez to Triple-A Syracuse in the final week of Spring Training, they envisioned him accumulating significant reps behind the plate, improving at a rapid rate and, eventually, earning a permanent promotion.

Instead, circumstances have changed the organization’s plans. The team learned Thursday that starting catcher Omar Narváez is likely to miss two months or more due to a left calf strain. The Mets placed Narváez on the 10-day IL on Friday, clearing the path for them to recall Álvarez, their top-ranked prospect per MLB Pipeline as well as the No. 1 overall prospect in the game. Álvarez is set to start behind the dish in the Mets' series finale vs. the Marlins on Sunday.

“I was surprised,” Álvarez said through an interpreter. “I got the call from the Triple-A manager, and I was eating at the time. I just said, ‘Damn, I’ve got to get ready to get on my flight.’”

Álvarez did not finish his meal, instead heading to Syracuse Hancock International Airport for the short trip to New York.

“The first thing that came to mind was that I needed to go back down there and work hard and prove myself, so that they can call me back up eventually,” Álvarez said through an interpreter following his March 22 demotion. “I think going down there, it’s going to help me get the reps that I really need and just get that experience to eventually come back up and succeed.”

A power-hitting Venezuelan who came to the Mets on a club-record $2.7 million signing bonus in 2018, Álvarez debuted last season with 14 plate appearances down the stretch, hitting his first career homer and even taking an at-bat in the postseason. He crushed 27 home runs with an .885 OPS last season in the upper Minors, though those numbers served to hide some of Álvarez’s lingering weaknesses.

Over his first 30 games at Triple-A, Álvarez hit .165 with a 29.8% strikeout rate. He whiffed in a third of his at-bats in the Majors (including the playoffs) and in 35.7% of them this spring while batting .107. Álvarez also struck out in 42.1% of his plate appearances early this season at Syracuse, though he hit two homers and slugged .688 in four games.

There is also the matter of Álvarez’s defense, which remains unpolished. But the Mets believe he has the tools to thrive behind the plate and intend to find out now, following a disappointing first road trip that saw them go 3-4 in Miami and Milwaukee. With Narváez sidelined until at least June, Álvarez figures to share time at catcher with Tomás Nido while also receiving reps at designated hitter.

At his best, Álvarez is capable of sparking a Mets team that ranked 24th in the Majors with 3.29 runs per game over the first week of the season. The team’s other option was Michael Pérez, a strong defensive catcher with a career .545 OPS in the Majors. Unlike Álvarez, Pérez is not on the 40-man roster. The Mets had signed both Pérez and Narváez this offseason in part because they wanted to avoid forcing Álvarez to the Majors before he was ready.

Time will tell if this move works for the Mets, who have so far resisted calls this season to promote two other top prospects, infielders Brett Baty and Mark Vientos. Álvarez is less of a finished product than those two, but his upside is immense and he comes to the Mets at a time of significant need.

Upon promoting Álvarez, manager Buck Showalter was unwilling to reveal how much playing time the prospect might receive, though he hinted that Nido will continue to see heavy use behind the plate. Nido started at catcher for Friday’s home opener, and he did the same Saturday with Kodai Senga on the mound.

“It’s kind of like a backup quarterback that gets drafted out of college,” Showalter said. “Everybody knows he’s going to be a really good player, but the time he spends as a backup is very valuable, too. Tomás is pretty good, OK? He does a great job for us.”