Ross, 24, struggled to a 5.01 ERA and 4.98 FIP in 73.2 innings at the big-league level for Washington this year before going down with arm trouble. The surgery will cost him the rest of this season and most of the 2018 campaign.
Washington had been using Ross as a fifth starter behind Max Scherzer, Stephen Strasburg, Tanner Roark and Gio Gonzalez, so his absence means they will need a replacement for the stretch run. Veteran Jacob Turner and top prospect Erick Fedde count as in-house options, with Fedde seen as potential candidate to receive a big-league call-up for the first time.
The Nats could also look for rotation reinforcements on the trade market, though the club’s main focus in trades will likely be on getting bullpen help. Washington’s bullpen has struggled all year, causing general manager Mike Rizzo to look for middle and late-relief help throughout the market.
Ross has made 48 appearances (45 starts) since making his debut in 2015 and owns a career 17-13 record and 3.95 ERA in that span.