UPDATE (6 p.m. ET): It’s official: Mark Melancon is the newest member of the Washington Nationals.

ORIGINAL STORY: The Washington Nationals reportedly have made a significant move to upgrade their bullpen.

The Nationals have acquired closer Mark Melancon from the Pittsburgh Pirates in a multi-player trade, FOX Sports’ Ken Rosenthal reported Saturday, citing sources. Washington will send relief pitcher Felipe Rivero and left-handed pitching prospect Taylor Hearn to Pittsburgh in return, according to MLB Network insider Jon Heyman.

Melancon has developed into one of Major League Baseball’s top closers over the past few seasons. He saved an MLB-best 51 games in 53 opportunities for the Pirates last season and entered Saturday with 30 saves in 2016 to go along with a 1.51 ERA and a 0.96 WHIP.

That’s good news for the Nationals, who have received inconsistent results from current closer Jonathan Papelbon of late. The former Boston Red Sox right-hander has failed to pitch a full inning in each of his last three outings, allowing a total of seven runs over that span to boost his ERA to 4.41 on the season.

Washington didn’t even use Papelbon on Friday night, relying on two different relievers to record three outs in a save situation in the ninth inning. Now, the club adds an All-Star closer to a bullpen that already is tied for the best ERA in baseball at 3.05.

The Pirates, meanwhile, seem to be getting a pretty good deal themselves.

Thumbnail photo via Geoff Burke/USA TODAY Sports Images