Bone marrow suppression causes a deficiency of blood cells. It can involve the white cells in addition to the red cells and platelets. Bone marrow suppression often times causes anemia, neutropenia, a decrease in platelet counts or all three. I'm not sure as to how you would go about figuring out what's causing the neutropenia as they both can cause it. Maybe someone else will know a little more about it then I do I hope this helped, have a good day!