Multiple sources report that the Pirates have traded closer Mark Melancon to the Washington Nationals for lefty Felipe Rivero and pitching prospect Taylor Hearn.
Rivero throws 95+ and has five years of control, with the potential to be a late-inning reliever. Hearn was previously connected with the Pirates. They drafted him in 2012 but didn't sign him.
The haul for Melancon is not equivalent to what the Yankees got from the Cubs for Aroldis Chapman. Still, Rivero throws hard, has good peripherals, and is controllable. While dealing a key asset like a reliable closer in the middle of a pennant race is risky, the Pirates are receiving fair value from the Nats.
In his four years with the Pirates, Melancon has been a model of consistency in the closer role. It's likely that the Pirates will replace Melancon with Tony Watson or Neftali Feliz or both, at least in the short term.