Duvall would probably be a decent flip candidate but I doubt the Sox are willing to pay him the $10 million or so it would cost.
I don’t see any reason to sign Gallo at this point. He has proven he can’t hit above the Mendoza Line for four straight seasons. He’s a strikeout machine that occasionally hits a homer. I don’t see him being worth acquiring for any reason.
I’d rather see Eloy DH full time, hopefully stay healthy, and put up a monster first half so they can trade him for something. I’d also rather see Colas get the at bats in a lost season, rather than Duvall or Gallo. And ideally, the Sox get back an outfielder that will eventually be starting for them if Colas is a bust.