The Mets can still improve with what’s left on the relief pitching free agent market

Aside from Craig Kimbrel, who the Mets were never going to be in on, the relief market has grown thin. All of the top options have signed, and while the Mets have two strong bullpen anchors in Edwin Diaz and Jeurys Familia at the back end, the rest of their bullpen consists of Seth Lugo—who is pitching on a partially torn UCL and could be slotted in as the team’s sixth starter—and a bunch of question marks.

Currently, the rest of the bullpen would be made up of some combination of Robert Gsellman, Kyle Dowdy, Paul Sewald, Tyler Bashlor, Jacob Rhame, Drew Smith, Daniel Zamora, Luis Avilan, Hector Santiago, Eric Hanhold, and Stephen Villines. My love for Villines aside, that’s not an inspiring group, as most of these guys have utility as shuttle arms, not potential late-inning options. Lucky for the Mets, there are still a handful of good options and a plethora of depth relievers available.

Three top options

Three options stand above the rest, with excellent peripherals backing strong marks in cFIP and DRA-, the best available ERA predictors in which 100 is average for both and every point less than 100 is one percentile better than league average. In an ideal world, the Mets could bring in all three of these guys, all of whom should sign cheap contracts at this point in free agency.

• Tony Sipp was downright elite in 2018, running a 1.86 ERA and a 2.41 FIP in 38.2 innings after two seasons with a FIP over 5. Almost all of that improvement was due to a stupendous drop in HR/FB rate, which went from roughly 20.0% to a minuscule 2.6% last year. His velocity was roughly 1 MPH faster across the board, and he ditched his sinker entirely, so there’s reason to think at least some of this improvement is real. Even if he regresses into the 10% HR/FB range, he’s still a viable late-inning option—and one who should be available at a bargain. Because of that, he’s the best option both in this group and the market as a whole.
• Oliver Perez—yes, I’m serious—was quietly brilliant last year, posting a 75 cFIP with a very un-Perez-ian 30% K-BB%. He wasn’t just a LOOGY, either, holding lefties to a .213 wOBA and righties to an even better .138 mark. The sample size wasn’t very big at 32.1 IP, but dropping his sinker in exchange for more four-seam fastballs and living on the outside corner did wonders for him in 2018. The Mets still need a reliable lefty reliever in the bullpen, and while there’s a good chance he turns back into a pumpkin, investing a couple million dollars for a chance at another 40 elite innings out of the one-time Met is a good gamble.
• While his ERA the last two seasons hasn’t been impressive (3.56, 4.14), Sergio Romo has maintained great peripherals, posting a cFIP roughly 20% better than league average since 2017. That’s a step back from his days in the back of San Francisco’s championship bullpens, but it’s still very valuable. Romo struck out more than a batter per inning last season, kept his walks under control, and even opened a couple of games for the Rays down the stretch. Getting out of the AL East to some less homer-friendly environments would help Romo greatly, and a seventh-inning job with the Mets would be an ideal landing spot.

Usable experience

Beyond the top three options, there are several other veteran relievers who could plug the holes in the Met bullpen. They don’t stand out as much as those above, but they all have above-average peripherals and predictive metrics.

• Tyler Clippard, another former Met, has seen his strikeout percentage steadily rebound since the Mets acquired him during a down year in 2015, and he’s now back to peak levels. He gives up more hard contact these days, however, reducing his ability to limit hits and leading to more home runs. Still, DRA- is a big fan at 79, and like Romo he could benefit from getting out of the AL East.
• Zach Duke is an alternative to Perez as a reliable lefty relief option. He’s not quite as good against lefties (.267 wOBA) and is a true LOOGY that can’t get righties out. Despite those warts, he’s a better option than slotting Luis Avilan into the major league bullpen from the jump.
• While his ERA has fluctuated and he missed a good chunk of 2018 with injury, Tony Barnette has consistently been pegged at about 10% better than league average by both cFIP and DRA-. He doesn’t blow people away with gaudy strikeout numbers, nor does he induce a stupendous amount of ground balls. However, he’s a steady, useful middle reliever that can handle the seventh inning if required, and that reliability is what’s missing from the Mets’ bullpen.
• Brad Brach is the sketchiest option in this group. His strikeout and walk rates have been moving in the wrong direction for the past two seasons, and a move to the NL East late in 2018 wasn’t particularly helpful. Despite that, he’s kept his ERA in roughly the mid-3s, and ERA predictors peg him as an above-average option.

Average or Worse

There are several other older relievers, most with good strikeout rates and home run problems, floating around with roughly average ERA predictors. Adam Warren, Shawn Kelley, Aaron Loup, and Fernando Salas fit into this group. These guys aren’t particularly interesting to talk about, however, and I’d rather touch on a couple potential under-the-radar minor league signings.

• After being a disappointing starter, Brandon Maurer excelled in a new role for the Mariners in 2014. He posted a 1.85 FIP as a reliever, supported by a 22.0% K-BB%. That success carried over the next two years after a trade to the Padres. 2017 was a different story, though. Despite strong peripherals and a 3.93 FIP, Maurer’s ERA was disastrous and only got worse after a midseason trade to the Royals. Things didn’t improve at all in 2018, either, as his walk rate ballooned to a ludicrous 7.18 per nine innings, and his ERA and FIP followed suit. I can’t pinpoint what exactly led to Maurer’s downfall; his velocity and zone profile remained largely the same. Perhaps a greater use of his slider was a poor choice, or maybe he was tipping his pitches. Whatever the case, Maurer was recently a good reliever and there are no obvious red flags in his decline, making him a good bounce-back candidate.
• Prior to 2017, Nate Karns was a back-end starter who struck out a lot of guys despite mediocre fastball velocity and struggled with home runs (a good comp would be Mike Fiers). After a trade to the Royals and a promising start to the season, Karns needed surgery for Thoracic Outlet Syndrome, and he missed all of 2018 with a non-specific elbow injury. That’s not a very encouraging track record of health, but the strikeout stuff could still be in there. Perhaps Karns could stay healthier as a reliever who can just air things out for an inning at a time, or maybe he’s better suited as a swing-man type. Either way, he should be available for next to nothing, and his track record of strong peripherals makes him a big potential bargain.