So rather than just rehashing possible adds and subtractions, I thought it might be wise to look at the current, under-contract, depth chart, as of today, for 2015.
Here is the breakdown of Boston's 40-man roster (per redsox.com)
Pitchers (17): Matt Barnes, Drake Britton, Clay Buchholz, Rubby De La Rosa, Edwin Escobar, Heath Hembree, Joe Kelly, Tommy Layne, Edward Mujica, Anthony Ranaudo, Eduardo Rodriguez, Junichi Tazawa, Koji Uehara, Allen Webster, Alex Wilson, Brandon Workman, Steven Wright.
Catcher (4): Dan Butler, Ryan Lavarnway, Blake Swihart, Christian Vazquez.
Infielders (10): Xander Bogaerts, Garin Cecchini, Sean Coyle, Juan Francisco, Brock Holt, Will Middlebrooks, Mike Napoli, Dustin Pedroia, Travis Shaw, Jemile Weeks.
Outfielders (8): Mookie Betts, Jackie Bradley Jr., Bryce Brentz, Rusney Castillo, Yoenis Cespedes, Allen Craig, Daniel Nava, Shane Victorino.
Designated hitter (1): David Ortiz.
Here's how I would order them with more specific breakdowns by position:
(I've allowed for some players to be listed at multiple positions)
C -- Vazquez, Butler, Lavarnway, Swihart
1B -- Napoli, Nava, Craig, Shaw
2B -- Pedroia, Weeks, Holt, Betts, Coyle
SS -- Bogaerts, Weeks
3B -- Francisco, Holt, WMB, Cecchini
LF -- Cespedes, Nava, Craig, Brentz
CF -- Castillo, Betts, Vic, JBJ
RF -- Betts, Vic, Nava, Craig
DH -- Ortiz, everyone else