Nearly every analyst feels the future is bright for this 21 year old middle infielder, but when will his future with the big league club happen? I believe it should happen next year.
With David Ortiz retiring at the end of the 2016 season Boston will have an opening at the DH spot that they haven't had in many years. In addition they have a first baseman who would be better as a DH in Manny Ramirez. My suggestion is this, after 2016 move Ramirez to DH. That opens up first base for Travis Shaw who currently plays third. With third open you could bring up Moncada and let him play there as scouts have said he can play second or third.
Not only have you improved your defense by getting Ramirez off the field, but three fourths of the Red Sox infield would be 26 or younger.
It is unlikely that Moncada starts 2017 with the big league club, but if the Red Sox are reading this they really should give it some thought.