murphy is a starter (according the mets' depth chart.) the blue jays' site shows snider as 1st on depth chart in left. snider is the most droppable of your guys b/c he likely will be in a platoon, more so than murphy. the next droppable one is shoppach in my opinion. he's behind martinez. unless you know something about him taking over the starting gig, i'm not sure you need a back-up catcher.
if you can wait to see if murphy starts the season, while snider doesn't, then i'd drop snider for him.
help me please: viewtopic.php?f=26&t=375376
OF: Ethier, Jennings, Willingham, Quentin
BN: De Aza, Pagan, Aviles
P: Felix, Price, Buchholz, Lynne, J. Johnson, Wandy, Valverde, Jansen, Chapman, Betancourt