Per Jeff Passan of Yahoo Sports, Washington is "engaged in multiple discussions to trade starter Tanner Roark."
Sources: The Washington Nationals have engaged in multiple discussions to trade starter Tanner Roark, who is a year out from free agency and could make upward of $10M in arbitration. The Nationals continue to look at free agent pitchers to supplement their rotation.
— Jeff Passan (@JeffPassan)
December 11, 2018 Roark has been a part of the Nats rotation since the latter part of the 2013 season, compiling a 64-54 record and 3.59 ERA in 182 appearances (141 starts) over that span.
He finished tenth in Cy Young voting after a stellar 2016 season in which he won 16 games and had a 2.83 ERA, but has struggled for the same consistency in the last two years. As Passan notes, Roark could be set to make eight figures in arbitration.
But it sounds as if the Nats plan to fill those spots via free agency like they did with Corbin, a number of veteran arms still available on the market.