The Washington Capitals hoped a five-day break between games would allow them to regroup after a hectic schedule that included a coaching change and, just as important, to get healthy. They accomplished one of their two goals. When the Capitals make their first visit to Prudential Center, the New Jersey Devils' sparkling new arena in downtown Newark tonight, the team will be more familiar with the intricacies of interim Coach Bruce Boudreau's style of play. But they'll be far from healthy with veteran center Michael Nylander joining the list of injured players yesterday. "It is what it is," Boudreau said, shrugging, when asked about the injury situation. "If somebody is out, someone has to come in and be just as good as that guy." What exactly happened to Nylander remains a mystery.