I'm just not sure. Junior Lake will play second I'm assuming, Javier Baez will play short, and Kris Bryant at third. Then at first there's Anthony Rizzo. I think Castro is odd man out. They might just take on Dozier to be a fill in for a year or so for Lake or Baez. Plus they get prospects. New deal for Castro would be; Brian Dozier, Aaron Hicks, And Travis Harrison (who could move to corner outfield position).