Could the National League’s best 2020 bullpen reside in … Queens?

Yes, Mets relievers were the club’s Achilles heel this past season, finishing 12th of the 15 NL clubs with 0.7 WAR, per FanGraphs. The club got incredible performances from stars like NL Cy Young Award winner Jacob deGrom and NL Rookie of the Year Pete Alonso, and still finished outside the postseason bracket. The bullpen (4.99 ERA, 27 blown saves) was the biggest culprit.

But, on paper, FanGraphs’ Steamer projection system has the Amazins’ bullpen topping the Senior Circuit next year with an even 5 WAR, just behind the Rays and Yankees for baseball’s third-best relief unit. On paper is the key phrase, of course; Mets fans will tell you as quick as anyone that the best-laid plans can very often go awry. But New York finished just three games back of Milwaukee (4.1 bullpen WAR) for the second NL Wild Card in 2019. Tack on an additional 4 WAR to the Mets’ ‘pen, as Steamer believes, and, well, you can start to see how much that turnaround would mean.

Remember, projection systems are meant to be conservative -- so a 4-win jump by a bullpen unit warrants some examination. Here’s the rebound path that Steamer envisions in Flushing.

1) Get Edwin Díaz right

This was the first stated goal of the offseason for general manager Brodie Van Wagenen and new manager Carlos Beltrán, and it's central to any dreams of an elite Mets bullpen. The good news is that, for a reliever who struggled to a 5.59 ERA last season, there are about as many encouraging signs as could be. Díaz’s fastball velocity (97.4 mph) remained top-of-the-line, as did his strikeout rate (39%). His .207 expected batting average, calculated by Statcast using batted-ball quality and punchouts, finished in the 88th percentile. It really does appear that, with a reduction of the homers and walks that plagued him in ‘19, Díaz could spring right back to form. Improving his slider command will be essential.

Getting Díaz back to Steamer’s 2 WAR projection basically means returning him to his ’16 rookie form with the Mariners (1.9 WAR, 2.79 ERA, 15.3 K/9). The Mets probably shouldn’t expect him to match what he did in ’18 (3.5 WAR, 1.96 ERA, 57 saves in 61 opportunities), which was a career year for anyone. A performance somewhere between the extremes of ’18 and ‘19 gives New York an excellent closer.

2) Keep Seth Lugo in the ‘pen

Lugo still wants a rotation spot, but the Mets did the right thing in signing back-end starters Rick Porcello and Michael Wacha to keep Lugo as a bullpen ace. There’s no question that Lugo’s stuff plays up in relief, with his fastball carrying more bite (91.9 mph average as a starter in 2017, 94.5 mph as a reliever in ’19) and his elite-spin curveball getting less exposure if he goes through the lineup only one time.

This is a classic case of “if it ain’t broke, don’t fix it;” you don’t move one of baseball’s best relievers (91st percentile K%, 99th percentile xwOBA -- Statcast’s all-in-one metric that considers batted-ball quality, walks and strikeouts) out of the bullpen. Steamer sees Lugo coming back to Earth slightly in 2020 (2.2 WAR to 1.2), but he and Díaz form an excellent 1-2 punch, if both of them are clicking.

3) Dellin Betances rises again

This really depends on how soon Betances can hit the ground running after shoulder, lat and left Achilles injuries wiped out his 2019 campaign. But signing Betances was the upside move of the winter for a team that, quite frankly, needed to take a risk like this with its bullpen.

With his 32nd birthday coming in March, Betances isn’t the young buck he used to be. But Steamer’s projection (55 innings, 3.06 ERA, 34.2% strikeout rate), even with consideration for his age and injuries, is based on an incredible track record: Five consecutive 100-K seasons from 2014-18, and the fourth-highest career strikeout rate in history. The Mets’ best-case scenario has a completely healthy Betances giving them a three-headed monster with Díaz and Lugo. But even, say, a 75th-percentile version of Betances adds another punchout artist to this mix.

4) Justin Wilson eats more innings

Wilson’s health is integral to the Mets’ hopes for a league-best ‘pen, and he should have the inside track for a seventh-inning role if Lugo bounces around as the high-leverage rover. The southpaw was very good in 2019, shutting down platoon advantages (.687 OPS allowed to righty batters), stifling loud contact (98th percentile hard-hit rate, min. 100 batted balls allowed) and raising his ground-ball rate back over 50%. The Mets just need more of that; elbow inflammation essentially wiped out Wilson’s first half of the season.

Steamer sees some slight regression (2.54 ERA to 3.67) over a bigger workload (39 innings to 60), but the Mets would gladly take that for a lefty who can rack up strikeouts on both sides of the plate.

5) Jeurys Familia bounces back

Familia is far from a known quality at this point, and the Mets are crossing their fingers for a second career resurrection after Familia righted the ship once in 2018 (3.13 ERA, 2.65 FIP) before crashing back last season (5.70 ERA, 4.88 FIP). But aside from a blip two years ago (suspension, arterial clot in his shoulder), Familia has been an innings eater, and Steamer estimates he’ll put up another 60-inning campaign in ’20. Many of them will be quality innings, in Steamer’s eyes (3.92 ERA, 0.4 WAR), and simply having Familia as a contributor instead of a detractor (-0.2 WAR in ’19) counts as a win in this dream scenario for the Mets.

Like Díaz, Familia’s velocity stayed largely intact through the struggles, so this is another mechanics and command project (career-high 15.3% walk rate) for Beltrán and his staff.

6) The middle innings become less adventurous

Getting the ball to Wilson, Betances, Lugo and Díaz might be the biggest question mark of all for the Mets, who just never seemed to have that bridge solidified in 2019. New York’s list of negative-WAR contributors was simply too long, from Daniel Zamora to Corey Oswalt to Drew Gagnon to Wilmer Font and so forth.

This is where Van Wagenen’s rotation additions could help; either Wacha or Steven Matz figures to be the odd-man out, and maybe one of them is better suited for a long-relief role. Brad Brach turned things around after he signed with the Mets in August, and Robert Gsellman showed flashes (88th percentile hard-hit rate and 96th percentile average exit velocity allowed) despite his inflated 4.66 ERA. Perhaps Familia’s status as the unit’s No. 5 option, and thus more of a middle-innings role, is more appropriate at this point of his career.

Putting all this together is easily the biggest challenge for Beltrán, who, as a first-year manager, will immediately be under pressure for his skills as a bullpen tactician. On paper, at the very least, he might have the tools to pull it off.