The Nationals have traded for All-Star closer Mark Melancon, and that means a demotion to the setup role for struggling closer Jonathan Papelbon. In a weirdly funny twist, this exact scenario happened with the Nationals last season, but it was Papelbon taking the job from someone else. And it did not go well. At all.

It was July 28 when the Nationals acquired Papelbon, and then-closer Drew Storen offered up a reportedly peeved "no comment" when asked about the deal. The Nats had a one-game lead in the NL East. From that point forward, they would go 31-33 while the Mets went 38-24 and won the division by seven games.

Storen was a mess. Before the deal he had closed down 29 saves in 31 chances with a 1.73 ERA, 1.02 WHIP and 44 strikeouts against nine walks in 36 1/3 innings. Yes, those are elite closer numbers. After the deal, Storen would blow three saves against only five holds. He had a 6.75 ERA and 1.29 WHIP, making him one of the worst relievers in baseball during this span. He also ended his own season prematurely by injuring himself punching a locker.

Papelbon himself blew two of his nine save chances while delivering a 3.04 ERA. He wasn't bad, but wasn't great. The enduring image of Papelbon in a Nationals jersey in 2015 was of him choking the NL MVP, Bryce Harper, in a dugout altercation that got him suspended for the rest of the season (along with an MLB suspension for throwing at Manny Machado).

Jonathan Papelbon grabbed Bryce Harper's neck in a dugout fight.

It's hard to spin it any other way. The trade for Papelbon in 2015 was an utter disaster for general manager Mike Rizzo.

This time around, Papelbon is already struggling. He has coughed up seven earned runs and four walks in his past three outings while only recording three outs. His ERA is up to 4.41. His walk rate is way up (3.6 BB/9 vs. 1.7 BB/9 last season).

We know from seasons past that Papelbon isn't shy about his feelings on personnel issues and that he definitely wants to always be the closer. We do have this:

Otherwise it's a bit of a guessing game as to what is going on in Papelbon's head. No one could convince me that he's happy, and I would be surprised if he wasn't at least a little bit annoyed. Again, though, we just don't know.

It's not a stretch to say that the trade last season ruined Storen and is at the minimum slightly responsible for the D.C. demise.

Melancon is an elite closer. He doesn't have the huge name, but he gets the job done as well as anyone. It's an obvious choice to upgrade closer with Melancon over Papelbon, but there's a trickle-down effect. If Papelbon doesn't prove effective in the eighth inning, it makes the entire bullpen vulnerable much in the way Storen falling apart hurt the team last season.

The Nationals have a very good bullpen overall. They entered Saturday tied for an MLB-best bullpen ERA at 3.05. Melancon makes it that much better and a Papelbon rebound gives them a very scary 8-9 duo at the back end. That is, so long as Papelbon doesn't pull a Storen. The shoe is on the other foot, for sure.