Again not keen on strikers and goalkeepers as on field captains,
Personality and the ability to command the respect of the rest of the team are important, lets face it being able to bawl out a fellow team mate in full view of a capacity crowd and have the respect to get away with it with only positive outcomes is no mean acheivement, Goal keepers and strikers can be disconnected from the opposite end of their team for significant periods so this communication gets hampered.
Also the ability to lead by example is also vital, and midfielders are ideally placed to raise the game by active involvement as opportunities to do so are frequent, again keepers and Strikers tend to have to wait for their moments, midfielders especially can create them..
So midfielders with the necessary authority, respect drive and nouse are the ideal candidates.
As for Hammond, I reckon he will lift his game yet again, he will never be the most skilled midfielder, but box to box he puts in the graft and does the dirty work, those who play around such players appreciate them. Provided he does justify his berth in the staring 11 keep him captain. But dont put hiom in the 11 just because he's captain, if that happens it's time for a new captain.