I don't know why, I just don't trust Washington. Their offense is wildly inconsistent. Reminds me of the Red Sox, score in chunks.... Have a couple massive games, but then can go an entire series and struggle to score runs. They have some decent pitching, though I think the Rays and Astros are way better.
Doubt Nats or Cards give the Yanks too much trouble. Maybe if Scherzer pitches they win that game, but that's about it.