Gui Yuan “Itchy” Xu is just one of the guys playing rookie ball for the Orioles in Sarasota, Fla. Like the 34 others on the roster, he watches Orioles games at Camden Yards on television, dreaming of what it’d be like to take that field. But unlike his teammates, and unlike every other player in professional baseball, Xu is from China, which has yet to send an athlete to the Major Leagues.