I think the defense has potential to be solid. Yoan, TA, and Madrigal all have above average potential on defense. Abreu is obviously horrendous and lazy at 1B. Robert will be an absolute stud out there. Eloy and Mazara, meh.
Bottom line is the Sox have guys who are already above average or have the ability to be above average at the difficult positions. They'll be fine on defense.