WASHINGTON, D.C. — Cam Schlittler was at his locker a few hours before game time on Saturday, a dark hoodie practically covering his face. His chair faced inward. He spoke to no one. All that was missing was the No Visitors Allowed sign. It wouldn’t be long before Schlittler would pitch one of his most impressive games in what’s already a breakthrough season. Not because the Yankees beat the Nationals, 4-2, or that Schlittler finished in double digits in strikeouts.