4:08pm: MLB.com's Jonathan Mayo reports that the Nats get righty Ryan Mattheus and Robinson Fabian in the deal.
2:20pm: The Rockies acquired lefty reliever Joe Beimel from the Nationals, according to Chico Harlan of the Washington Post. The Nats received two minor leaguers, says SI's Jon Heyman via Twitter. Beimel, 32, has allowed a .233/.288/.417 line to lefties this year. He has about $800K left on his contract and projects as a Type B free agent after the season.