One article on Rule 5 by Ben Kairalla says ...
It’s a certainty that Downs will be protected. It’s also very likely Jimenez and Bello are protected as well.
Beyond those three, the right-handed pitching trio of Ward, Crawford, and Winckowski all rank among the Top-30 Red Sox prospects, and could provide depth to a team looking to add fresh arms and new faces to their pitching staffs without having to trade for a pitcher or look to the free agent market for pitching.
Players currently on the 40-man roster who my find themselves in danger of being removed to prevent the Rule 5 eligible prospects from being drafted include: Eduardo Bazardo (RHP), Phillips Valdez (RHP), Ronaldo Hernandez ©, Hudson Potts (1B/3B), Jeisson Rosario (OF). Another player who could be at least temporarily jettisoned from the 40-man roster is infielder Jonathan Arauz.
n all, the Red Sox have nearly 50 players in their minor league system that are Rule 5 draft eligible. Beyond the top organizational prospects mentioned above, other recognizable names to keep an eye on include outfielder Franchy Cordero and relief pitcher Durbin Feltman.