Sterling Marte patrolling centerfield would be nice. Miguel Amaya would be expendable is we keep both Contreras & Caratini. But I think the Pirates would want more. Our farm system is really not loaded right now and we really can't afford to trade away much more of it.
Moving past Marte- the Braves are reportedly eyeing Bryant, and allegedly have discussed a couple of OF as a return- Austin Riley and Drew Waters.
Marte would also be a good addition, and would most likely come cheaper in trade than dealing KB to Atlanta, but either way, looks like the Cubs are honing in on a center fielder.