After a 14-month whirlwind that took him from the Big 12 to the big leagues and the World Series, left-hander Brandon Finnegan reported this month as the youngest pitcher in Royals camp and the most fascinating component of their roster construction. Team officials consider him their best left-handed option for the big-league bullpen and hope he could anchor a starting rotation. But he is still learning the etiquette of his clubhouse, and experiencing the rights of passage inflicted on rookies.