LAS VEGAS — In a thin free-agent market for high-end lefty relievers, Andrew Miller stands virtually alone to the Mets.

Despite a 2018 season below his standards, Miller checks the boxes as somebody with a dependable track record who can be trusted in high-leverage situations and won’t be limited to a lefty specialist’s role. That Miller has pitched in New York, with the Yankees, and proven his mettle only helps his case.

But there is also a sense within the industry that 33-year-old Miller has been overused in recent seasons, and his 2018 numbers should serve as a warning sign: In only 37 appearances for the Indians because of shoulder, knee and hamstring injuries, Miller went 2-4 with a 4.24 ERA and 1.382 WHIP.

“There’s definitely red flags,” a major league talent evaluator said. “All these free-agent relievers have red flags.”

The Mets helped solve a significant chunk of their bullpen deficiency by acquiring closer Edwin Diaz from the Mariners in the deal that also netted Robinson Cano and sent Jay Bruce, Anthony Swarzak, Jarred Kelenic, Justin Dunn and Gerson Bautista to the Mariners. But the Mets also realize another quality reliever is needed to address a bullpen that was among the worst in the major leagues last season.

David Robertson and Joe Kelly are among the others who could fit in that setup role, but general manager Brodie Van Wagenen has also pointed out the Mets’ lefty need. Zach Britton, who spent much of last season with the Yankees, is on the Mets’ radar, but the fact he’s been shopped as a closer — and would command a significantly bigger contract than Miller — has team officials skeptical he’s a fit.

Van Wagenen’s payroll parameters are unknown, but the GM arrived at these winter meetings with the idea he needs to upgrade at catcher and add a right-handed bat for the outfield. Those needs will likely preclude him from paying a closer’s dollars for Britton, with the 24-year-old Diaz already on board.

Miller’s best work came with the Indians during the team’s pennant run in 2016, and the lefty has a strong working relationship with manager Mickey Callaway, who was previously Cleveland’s pitching coach. Miller’s veteran presence would be welcomed to a bullpen that has several young pieces. In addition to Diaz, the Mets have Seth Lugo and Robert Gsellman as part of their bullpen and continue to evaluate relievers such as Drew Smith, Tyler Bashlor, Eric Hanhold, Bobby Wahl and lefty Daniel Zamora.

But the Mets aren’t alone in pursuing Miller — he’s been linked to several teams — and Plan B would likely be a right-hander such as Robertson or Kelly.

Robertson’s preference is a team close to his Rhode Island home, and the Red Sox have reportedly shown interest in him. The right-hander has a history with Mets pitching coach Dave Eiland from Robertson’s first stint with the Yankees.

Kelly emerged as a significant bullpen piece for the Red Sox in their World Series-winning run and would bring another power arm to the equation.