D.C. United’s season was going swimmingly until a week ago. Since then, they’ve been handed a rough loss and a snooze-inducing scoreless draw — both at home — while learning what life is like when Wayne Rooney isn’t available. They get a chance to get back on course today, though, as they head to the Rockies to take on the struggling Colorado Rapids. With a whopping 16 goals conceded to start the season, the Rapids look vulnerable, but United can only take the three points if they show marked improvement over their last two outings.