The Boston Red Sox need to protect certain players by moving them to the 40-man roster to prevent any rule 5 losses. Marco Hernandez, acquired as a PTBNL for Felix Doubront, is one such player. An impressive season at Portland and Pawtucket certainly has moved Hernandez up in the eyes of the scouting department.
Trades are always a possibility. The rumor mill is rampant with various scenarios concocted in which the Red Sox acquire an ace or a notable talent and moves have already begun. You need a space in a deal in which more bodies arrive than exit so a personnel shift takes place.