After Monday’s acquisition of Joey Lucchesi from the San Diego Padres, the Mets’ starting rotation seems mostly set. Jacob deGrom, Marcus Stroman, Carlos Carrasco, Lucchesi, and David Peterson represent five capable starters, and if any of them should falter, Robert Gsellman, Steven Matz, and Seth Lugo are all solid options to step into the rotation for a start or two.

With the rotation set, the Mets can now focus on the bullpen — and thank goodness. The Mets need left-handed relief, and they need it badly. Ask a Mets fan what the team’s biggest need is, and they’ll probably mention third base or left field. But at those positions, the Mets at least have okay options. In left, they can use Dominic Smith. At third, they can platoon J.D. Davis and Luis Guillorme. Those aren’t foolproof plans, but they’re not gaping holes either.

Speaking of gaping holes, do you know who the Mets’ left-handed relievers are? At this moment, they have four: Steven Matz, Stephen Tarpley, and Daniel Zamora that are on the 40-man roster and they signed Jerry Blevins to a minor league deal.

Matz pitched to a 9.68 E.R.A. in 2020. Zamora has thrown 17.2 innings in his career, and didn’t pitch in the majors in 2020. Stephen Tarpley has pitched 44.2 innings in his career, and has pitched to a 6.65 E.R.A. Blevins didn’t pitch in 2020.

Sure, the Mets could use a left fielder or a third baseman — but their need for left-handed relief is dire, and far more pressing.

Fortunately, the Mets seem like front-runners for Brad Hand. While reports last week that the Mets and Hand were on the verge of a deal turned out to be premature, Hand and the Mets are a perfect match. Hand makes so much sense for the Mets that it would almost be shocking if they didn’t sign him. He has a 2.70 E.R.A. over the last five seasons, and over his career has held lefties to a .552 OPS.

Hand is the most consistent left-handed reliever available in free agency, and the Mets should do everything they can to sign him. But if they miss out on Hand, they can quickly shift their attentions to a different target: Justin Wilson.

With the Mets in 2019 and 2020, Wilson put up a 2.91 E.R.A. and struck out more than 10 batters per nine innings. He’s actually been slightly better against righties than lefties in his career — righties have a .638 OPS against him, while lefties have a .651 OPS — but he’s excellent against hitters on both sides of the plate. He’s a lower profile name than Hand, so he shouldn’t cost too much, and he’s already proven that he can handle New York.

In fact, it might not be the worst idea in the world for the Mets to pursue both Wilson and Hand. They’re different pitchers: Hand shuts down left-handers, while Wilson is excellent against both righties and lefties. You can never have enough quality relief pitching. The Mets’ starting pitching staff is shaping up to be excellent in 2021, but starters can only do so much if the bullpen can’t hold a lead.

In the age of Steve Cohen, now that the Mets have acquired James McCann and Francisco Lindor and Carlos Carrasco all in one season, it’s easy to forget that to be great, baseball teams have to go beyond the big names. The 2015 Mets had a starting rotation stacked with superstars and big egos, but they wouldn’t have been nearly as successful as they were without quiet, excellent seasons in middle relief from Sean Gilmartin and Hansel Robles.

Even teams loaded up with stars need to do the everyday housekeeping that prevents leaks from becoming floods. Signing middle relievers is just about the least exciting thing a team can do in free agency. But it pays off with interest when the season comes, and the bullpen is not necessarily dominant, but is refreshingly competent and not a perpetual source of headaches and blown leads.

The 2021 Mets bullpen looks strong from the right side: Edwin Díaz, Trevor May, Miguel Castro, and Seth Lugo are all solid options. But on the left side, they have almost nothing. They certainly don’t have any left-handed relievers whose entrance into a close game will instill confidence. With Hand, Wilson, or both, that can change.

Sure, it would be exciting if the Mets signed George Springer, and it would be earth-shattering if they traded for Nolan Arenado or Kris Bryant. But big moves aren’t the only ones worth making. Just by signing a left-handed reliever or two, the Mets can immediately turn what is now a weakness into a strength.

Wilson and Hand won’t sell jerseys or season tickets, and they may not be All-Stars or Silver Sluggers. What they will do is close a gap in the Mets’ roster, and prove instrumental in helping the Mets protect leads and win games. Right now, that’s exactly where the Mets’ focus should be.