Dhoni is currently the no. 1 ranked one-day player. He has been consistent in one-dayers for a while. Maybe Indian guppies can enlighten us on this. These nominations take into account individual brilliance + consistency over the past year regardless of whether or not you won anything for your country. That ofcourse does not completely rule out bias.
These awards are based on consistent performance over a sustained period of time, and not just some flash in the pan win.
Probably thats the reason Afridi is not in the list.