The Sox were a 98 win team according to Pythagoras. Assuming everything else remained the same, for argument's sake, the loss of Papi would make us approximately a 93 win team.
I'm expecting some upgrades to the pen. I'm also expecting that Dombrowski will do something on the offensive front, though I don't think it will be a big move. Some players will improve, others will regress. Our offseason needs are not nearly as dire as some people are making them out to be.
IMO, we could start the season with the team we currently have and we would be a legitimate contender. I am not suggesting that we stand pat, but I think we would be good to go if we did.