Lin has some good defensive rankings by scouts. I trust what they say.
soxprospects.com..
Field: Above-average defensive potential at shortstop. Gets good reads off the bat and has range to both sides. Fluid actions, soft hands. Confident defender, reads the ball off the bat well and comfortable charging the ball. Has some versatility to play second base, third base, and center field.
Also, to me, Marrero's defense has been a bit of a let down. Maybe my expectations were too high to start.
soxprospects writes thids about DM:
Field: Plus defender. Extremely athletic. Not flashy, makes it look easy. As fundamentally sound as they come. Great body control and is able to throw from all angles and on the run. Active lower half with agility, quick lateral movements, and soft hands. Plus range and first-step quickness and reactions. Future gold glove potential.