Four of them are all but certain in Jonny Gomes, David Ross, Mike Carp and Xander Bogaerts. The fifth position player spot would seem to be between Quintin Berry, John McDonald and Jackie Bradley Jr.
Berry offers a pure stolen-base threat. Bradley has some speed, and he also brings a very strong glove in the outfield. McDonald, who is probably the underdog among the three, can play all over the infield.
"That's part of the greater discussions that we have as we kind of walk through any potential moves, any potential pinch-hit situations," said Farrell. "Who's available to give us further options if we choose to go to someone in the fifth or sixth inning? Do we have someone later on to hold back and cover us positionally? Those are all the conversations that are starting right now."
Then there is the bullpen, where there are probably seven spots available. Koji Uehara, Junichi Tazawa, Craig Breslow, Brandon Workman and Ryan Dempster seem to be definites.
Then there are the bubble candidates, which include four lefties -- Matt Thornton, Felix Doubront, Franklin Morales and Drake Britton.
Ian Browne is a reporter for MLB.com. Read his blog, Brownie Points, and follow him on Twitter @IanMBrowne. This story was not subject to the approval of Major League Baseball or its clubs.