NEW YORK — The New York Mets are losing yet another lineup regular for a long time.

Catcher Francisco Alvarez suffered a torn meniscus in his right knee during a swing on Tuesday night. Alvarez was placed on the 10-day injured list Wednesday, with Hayden Senger promoted from Triple-A Syracuse to take his place. Alvarez will undergo surgery as soon as possible, at which point the Mets will have a better idea of the severity of the tear and Alvarez’s ultimate return timeline.

The best-case scenario for a return from a meniscus tear would be around six to eight weeks. The worst case could imperil Alvarez’s season.

The IL is unfortunately a familiar place for Alvarez. This is his fourth trip there in the last three seasons: He tore thumb ligaments in both 2024 and 2025, sandwiching surgery for a hamate fracture early last season. Wednesday marked the 100th day of his career he’s been on the IL.

“You feel for the person and the human,” manager Carlos Mendoza said. “He hasn’t had that run of playing every day, going through struggles and finding a way to get through it. For him the past three years, it’s always been the injuries. He struggles, he gets hot, but then he gets hurt and misses significant time.”

Alvarez had not had any issues with the knee prior to the swing in Tuesday’s sixth inning, when he fouled back a Burch Smith fastball.

The injury, like all the ones the Mets have endured of late, comes at a bad time. New York’s offense has underperformed all season, and it needs all the help it can get at the plate. Luis Torrens, who will see the majority of the time in Alvarez’s absence, is an excellent defensive catcher. He does not present the same threat with the bat that Alvarez does, even when the latter is slumping as he had been of late.

With Alvarez on the IL, four of the Mets’ nine starters in their Opening Day lineup are currently sidelined. The timelines are also murky on Jorge Polanco, Luis Robert Jr. and Francisco Lindor. Juan Soto also missed around three weeks with a calf strain earlier this season.

This is the third meniscus tear a Met has suffered this season, with Alvarez joining Mike Tauchman and Jared Young. Are the Mets worried there’s a reason for that trend?

“We’re always looking, especially if guys continue to get hurt with the same injury. It’s hard to pinpoint,” Mendoza said. “The way it happened, too, with one swing and a guy who hasn’t reported anything. Yes, we’ve got to go back and see if there’s anything or something that we’re doing that’s affecting guys in that area.”

Young tore his meniscus in the second week of April and could be looking at a rehab assignment by the end of this week. Tauchman tore his in March and has yet to start baseball activities. Regardless of the severity of his tear, Alvarez’s road back will be more complicated because of the unique stress that catching places on the knees.

“Knowing Alvy, this guy’s going to do everything he can to get back on the field as quickly as possible,” Mendoza said. “But we’re looking at a knee, and he’s a catcher. It’s probably different than what Jared Young is dealing with.”