Yoshida was originally the fourth outfielder/non-starter. He’s only playing as much as he is due to Anthony’s injury. This has been pointed out multiple times, much like how the decision to sign Gasper was unrelated to negotiations with Alonso.
If the Sox signed Alonso, they have to move an OF (Duran) for a 3b, and likely not Durban. So who? What affect does that have? Or does Mayer play 3b, with Hamilton at 2b? Is that better?
So the bench Duran but play Hamilton. Plus still have Harrison.
Of course Story still had a hernia and Mayer unsurprisingly got hurt again. So yeah, Sogard, Hamilton and ?? as the starting infield…