last year we literally paid another team $11M to take our best pitcher (and this year's CY award winner) for a light-hitting, AAA suspect when (as the OP pointed out) we have a "wealth of infielders", so it totally makes sense to now trade our best hitter this year for someone who will flop. i wonder if the OP works in the Sox FO.
comparing him to Ellsbury is ignorant. there is no correlation between the two, other than they've played centerfield for the Sox. why not compare him to Ken Griffey Jr. or Willie Mays? just because Jacoby got hurt, Duran might get hurt? LOL. why not trade Casas? he's already been hurt and his defense sucks.