David Robertson has left the building. By “building,” we mean the trade market. Now that the former White Sox closer has been shipped off to the Yankees as part of a six-player swap that went down Tuesday night, we can officially put to bed all those Dave-to-D.C. rumors that had been floating around since what seems like the early 18th century, but has really only been since last winter.

That’s when Washington whiffed on the troika of free-agent closers -- Kenley Jansen, Aroldis Chapman and Mark Melancon -- prompting speculation that GM Mike Rizzo might swing a trade with Chicago. Rizzo did make a deal with the White Sox, only it had nothing to do with Robertson. Instead, he sent three top pitching prospects to the Windy City in return for outfielder Adam Eaton. Lacking a proven closer (among other things), the Nationals' bullpen proceeded to put up a first half that was, to use technical baseball jargon, bad.

Washington’s relievers were so awful -- their 5.20 ERA through the All-Star break was worst in the majors -- that even after Rizzo made a significant upgrade by trading for Oakland hurlers Ryan Madson and Sean Doolittle on Sunday, it seemed he might not be done. After all, as dependable as Madson and Doolittle are, neither was closing for the A’s. Whether Rizzo is finished making moves remains to be seen, but this much we do know: If the Nationals squeeze the trigger again between now and July 31 and acquire a closer, it won’t be Robertson.

Here’s the short list of candidates who haven’t left the building and could be in play for Washington:

Justin Wilson, Tigers: Even though he’s a lefty and Dusty Baker’s bullpen already has three southpaws (Doolittle, Enny Romero and Oliver Perez), Wilson probably makes as much sense for the Nats as any reliever out there. Of his $2.7 million salary, Washington would only be on the hook for about a million (his pro-rated pay) this season, a team-friendly figure for a club that just committed about $12 million to Madson and Doolittle, both of whom are under contract through the 2018 season. Besides being cheap, Wilson has been really good as Detroit’s closer (13 K’s per nine innings and an 0.91 WHIP). The problem is that the Tigers know that, and they also know that Wilson is under team control through 2018, which means their asking price could be steep, especially in a market that’s lacking for true shutdown relievers.

Brad Hand, Padres: Like Wilson, he’s a lefty. Like Wilson, his 2017 salary number ($1.4 million) is easy to swallow. Unlike Wilson, he’s under club control for another two-plus seasons. Not surprisingly, all accounts seem to suggest the Padres are looking for a hefty haul (see: Andrew Miller, 2016) in return for the setup man who was their only All-Star this year. Rizzo probably isn’t interested in spending that kind of currency. Not after what he gave up to get Eaton, and not for a guy who has never been a closer.

Zach Britton or Brad Brach, Orioles: Britton, who missed most of the first half with a forearm injury, is as filthy (and established) as any closer in the game when healthy and could give Baker the proven ninth-inning guy his bullpen is missing. In Britton’s absence, Brach has shown that he’s as versatile as any reliever in the game: A year after being an All-Star as a setup man, the 31-year-old righty has 16 saves and a 0.89 WHIP. Both Britton and Brach are under contract through 2018, so neither would come cheap. That’s secondary to the bigger sticking point, which is that the O’s and Nats -- geographic rivals who are separated by 40 miles and have long been embroiled in a legal dispute over TV revenue -- have never made a trade together. Don’t expect that to change now.

Kenley Jansen, Dodgers: Just kidding. Wanted to see if you were paying attention.

Pat Neshek, Phillies: The good news, if you’re the Nats, is that Neshek would only be a short-term rental, as his contract expires at the end of this season. As such, his price tag should be significantly kinder and gentler compared to the guys listed above. The bad news is that as lights-out as Neshek has been this year (1.17 ERA, 8.2 K/BB ratio), he’s not a closer and never really has been. If it turns out that Baker and Rizzo feel comfortable with Doolittle or Madson handling the ninth inning -- Doolittle got first crack against the Angels on Tuesday and converted a shaky save -- then Neshek could be a good fit.

Kelvin Herrera, Royals: It remains to be seen whether the Royals, who are three games out of the wild-card hunt but can’t seem to escape the gravitational pull of the .500 mark, will be peddlers or purchasers. It also remains to be seen whether Herrera -- whose 4.29 ERA this year is two runs higher than his combined ERA over the previous three seasons -- would be of much help to a contender. Given those two uncertainties, Washington doesn’t seem a likely landing spot.

AJ Ramos, Marlins: Will Miami sell? Check. Is Ramos a proven closer? Check. But over the past two seasons, he’s walking nearly five guys per nine innings and has a WHIP that’s closer to 1.50 than to 1.00. Not exactly a problem-solver for the Nationals. Even if he were, it’s hard to envision Washington being willing to fork over much -- which they might have to do since Ramos is under control through next season -- to a division rival.