Not all players in a team's minor-league system are eligible for the Rule Five Draft and need to be protected.   A player not on the 40-man roster is eligible for the Rule 5 draft if: the player was 18 or younger when he first signed a pro contract and this is the fourth Rule 5 draft since he signed, OR if he was 19 or older when he first signed a pro contract and this is the third Rule 5 draft since he signed.  So this is the first season that Purcey (as well as the others Chengy listed) is eligible for the draft, and, therefore, the Jays will have to add him to the 40-man roster or they will expose him to the draft.  

Chengy, I agree Gronk should be protected.  He's ready to contribute at the major-league level now so it is very likely someone will snag him and he will contribute to their bullpen throughout the season.   I don't think it's worth protecting Cannon, Griffin, or Santos.  Taubenheim is allright, but the Jays don't really need him.  Vermilyea might be nothing special, but his minor-league numbers suggest he doesn't beat himself and could be a useful, if low-ceiling, MLB pitcher.  I'd try to hang onto him.