I strongly doubt boston is done. Interestingly, they dealt away both Shaw and Moncada who would presumably both be names to consider for their 3B. They still have Sandoval and Holt but that's not very inspiring. They already have $172.8 mil committed to 2017 with another $26.6 in likely arbitration costs. With the luxury tax being roughly $190 mil if memory serves, they might need to look to trades. Sandoval makes $17.6 mil but it would surprise me if they can move him for anything useful given he's owed another $54.8 mil and hasn't been close to that value. Buchholz is set to make $13.5 mil. They could probably move him in this market.
There's a case to be made the cubs might shop Candelario to them. Devers is at least 2 years away and given Dumbrowski's MO who knows if he even remains with the sox long term if they develop some other need. Only 3Bs ranked higher than Candelario right now on mlb.com are Devers(A+), Matt Chapman(AAA), and Nick Senzel(A) and i'm dubious on Oakland trading Chapman given they need a 3B too. Other potential options, Rangers with Gallo(?), Rays with Longoria though would they trade in division?, Royals with Moustakas near FA, white sox with Frazier though if they were going to get him surely they would have made a bigger package with the Sale trade no? Those are the teams that come to mind.
Red Sox could also use some C help and maybe a DH though if Sandoval stays and isn't their 3B surely he DH's. Rotation looks great and their bullpen should be strong too.