Almost all of the Yankees' positions in the field are accounted for in 2017, with depth, from catchers Gary Sanchez and Brian McCann, to first baseman Greg Bird to their many outfield options. Dellin Betances will be the closer, of course.
The greatest unknowns will be in their rotation. Masahiro Tanaka has somehow become an underrated ace in spite of all of the attention he drew when he signed with the Yankees: He leads the American League in ERA and is a Cy Young candidate, with a 2.77 ERA and 12 walks and 68 strikeouts in his last 12 starts. CC Sabathia has one year remaining on his deal and given his successful transition from a pitcher who dominated with a mid-90s fastball to someone who has figured out how to get hitters out with a lot less than that. He'll presumably be at the back end of the Yankees' rotation.
The Yankees have to figure out who will man slots in the rest of the rotation, whether it be Michael Pineda, whose inconsistency is from inning to inning, and not just start to start, or Bryan Mitchell, who has had some good starts down the stretch this year, in a pennant race. The other day, Yankees manager Joe Girardi said that moving forward, there will be continued efforts to develop Luis Severino as a starting pitcher, to help with the evolution of the third pitch he needs to combat hitters a second or third time through the lineup.