The Washington Nationals are keeping a close eye on Oakland Athletics ace Sonny Gray, according to MLB Network's Jon Morosi.

The Nats are prepared to possibly trade for a starting pitcher and have continued talks with the A's, sources tell Morosi. Oakland and Washington were trade partners earlier this month in a five-player deal that sent relievers Ryan Madson and Sean Doolittle to the nation's capital and right-hander Blake Treinen to the East Bay.

Citing sources, Morosi writes that the Nats are ready to trade for a starter if Stephen Strasburg's arm discomfort turns into a long-term issue. Strasburg left Sunday's start against the Arizona Diamondbacks in the second inning with right forearm stiffness. Not to mention, righty Joe Ross is out for the season after undergoing Tommy John surgery.

Gray, considered one of the top starters available at the trade deadline, is 6-4 with a 3.66 ERA and 1.18 WHIP in 15 starts this season. The 27-year-old right-hander is under club control for the next two seasons.

Per Morosi, the A's are zoning in on teams that could provide them with a young outfielder in talks on Gray. The Nationals have two such pieces: 20-year-old Victor Robles, who was recently promoted to Double-A Harrisburg, and 18-year-old Juan Soto, who is on the disabled list for Low-A Hagerstown. Robles, who came in at No. 4 in Keith Law's midseason prospect rankings, is perceived to be the more valuable of the two, Morosi notes.

-- Alex Tekip