Relievers Henry Owens and Matt Lindstrom are the sexiest of the three due to their radar guns readings and attendent strikeout numbers, 74 in 40 IP in AA and 70 in 58.2 IP respectively. I expect both to be listed as sleeper candidates for saves despite Gregg's leg-up.
Personally, I like LHP Taylor Tankersley, but I can see him being deemed to valuable to pitch in just save siutations when his leftiness is need in the 7th and 8th innings aginst the most fearsome of left-handed batters.
Eric is a sharp guy and he could be completely correct about who is most likely to be the new closer for the Marlins. If you have to draft your fantasy team on Monday, it may be the way to go. But my feeling is this: if everything stays like it is now - Henry Owens will be given the first shot as the closer. Owens is gaining experience closing, and is doing quite well, in the Dominican Winter League.
I foresee Gregg being used in the "Oh, Crap! The starter is loosing it and there are guys all over the bases and we are endanger of letting this game get away. Get someone in there who can put an end to this." spot.
I completely agree that Tankersley is probably going to be used as mainly the setup man and in some important circumstances as the situational lefty out of the bullpen.
Spring training will tell more tales.