UPDATE: The Phillies will send $4.5 million to the Nationals to cover Papelbon's remaining salary this season, according to Svrluga.
UPDATE: The trade is official.
It took long enough, but the Philadelphia Phillies finally traded closer Jonathan Papelbon - to a division rival.
The Washington Nationals agreed to a deal with the Phillies to acquire Papelbon, according to FOX Sports' Jon Morosi.
Papelbon also be taking a $2 million pay cut in 2016 and will earn a guaranteed $11 million after sacrificing his vesting option for next year, which was worth $13 million.
The Phillies received prospect right-hander Nick Pivetta from the Nationals, according to Todd Zolecki of MLB.com.
Earlier today Jim Salisbury of CSN Philly was told by a baseball source with knowledge of the situation that "Papelbon will be traded." James Wagner of the Washington Post kept updates on the development throughout the afternoon.
That was followed up by a series of tweets:
Last week ESPN's Jayson Stark reported that the three original top suitors for Papelbon - the Cubs, Dodgers and Blue Jays - were no longer pursuing the right-hander, which fueled speculation that the Phillies may have missed their window to move him.
Papelbon, 34, owns a 1.59 ERA and 0.98 WHIP with 17 saves and 40 strikeouts in 37 games (39 2/3 innings). He'll now close for the Nationals while Drew Storen undertakes the role as setup man.