The paper cups, packs of sunflower seeds and water bottles inside the Washington Nationals’ dugout remained in their places, pardoned by the new, collected Stephen Strasburg. The first inning of his first spring training start had been, in Strasburg’s own words, “a bit of a debacle,” replete with a home run off the bat of a Lilliputian middle infielder. “Last year at this time, if he would have done what he did in that first inning, we would have seen gloves flying, cups flying,” shortstop Ian Desmond said. “He was pretty fairly composed today.” Over the next eight months, the Nationals may take the field some 200 times — 35 games in the Grapefruit League, 162 in the regular season and perhaps 20 or so more in October. “It starts now,” Strasburg said in the visitors’ clubhouse of Tradition Field on Saturday afternoon after he tossed 42 pitches over two innings in a 5-3 loss to the New York Mets in the Nationals’ spring training opener. It was his first appearance since the Nationals cut short his season last August.