A blood processing device, comprising: a pump system; a valve system; a centrifuge; and a controller configured to command the pump system and the valve system to cooperate to convey whole blood from a blood source into the centrifuge, execute an establish separation stage in which the centrifuge operates to separate the whole blood in the centrifuge into plasma and red blood cells and the pump system and the valve system cooperate to convey separated plasma and red blood cells out of the centrifuge, recombine the separated plasma and red blood cells as recombined whole blood, and convey the recombined whole blood into the centrifuge; execute a collection stage in which the pump system conveys the whole blood from the blood source to the centrifuge; the centrifuge separates the whole blood in the centrifuge into plasma, a buffy coat, and red blood cells; and the pump system and the valve system cooperate to convey at least a portion of the separated plasma out of the centrifuge and to convey at least a portion of the separated red blood cells out of the centrifuge for collection, with a fluid including the buffy coat remaining in the centrifuge; execute a platelet resuspension stage comprising a first phase in which the centrifuge is deactivated and the pump system and the valve system cooperate to circulate the fluid in the centrifuge through the centrifuge to form a homogenous mixture, and a second phase in which the centrifuge operates to separate the homogenous mixture into a platelet concentrate and red blood cells; and execute a platelet harvest stage in which the pump system and the valve system cooperate to convey whole blood from the blood source or at least a portion of the collected red blood cells into the centrifuge to convey at least a portion of the platelet concentrate out of the centrifuge for collection. a pump system; a valve system; a centrifuge; and a controller configured to command the pump system and the valve system to cooperate to convey whole blood from a blood source into the centrifuge, execute an establish separation stage in which the centrifuge operates to separate the whole blood in the centrifuge into plasma and red blood cells and the pump system and the valve system cooperate to convey separated plasma and red blood cells out of the centrifuge, recombine the separated plasma and red blood cells as recombined whole blood, and convey the recombined whole blood into the centrifuge; execute a collection stage in which the pump system conveys the whole blood from the blood source to the centrifuge; the centrifuge separates the whole blood in the centrifuge into plasma, a buffy coat, and red blood cells; and the pump system and the valve system cooperate to convey at least a portion of the separated plasma out of the centrifuge and to convey at least a portion of the separated red blood cells out of the centrifuge for collection, with a fluid including the buffy coat remaining in the centrifuge; execute a platelet resuspension stage comprising a first phase in which the centrifuge is deactivated and the pump system and the valve system cooperate to circulate the fluid in the centrifuge through the centrifuge to form a homogenous mixture, and a second phase in which the centrifuge operates to separate the homogenous mixture into a platelet concentrate and red blood cells; and execute a platelet harvest stage in which the pump system and the valve system cooperate to convey whole blood from the blood source or at least a portion of the collected red blood cells into the centrifuge to convey at least a portion of the platelet concentrate out of the centrifuge for collection. command the pump system and the valve system to cooperate to convey whole blood from a blood source into the centrifuge, execute an establish separation stage in which the centrifuge operates to separate the whole blood in the centrifuge into plasma and red blood cells and the pump system and the valve system cooperate to convey separated plasma and red blood cells out of the centrifuge, recombine the separated plasma and red blood cells as recombined whole blood, and convey the recombined whole blood into the centrifuge; execute a collection stage in which the pump system conveys the whole blood from the blood source to the centrifuge; the centrifuge separates the whole blood in the centrifuge into plasma, a buffy coat, and red blood cells; and the pump system and the valve system cooperate to convey at least a portion of the separated plasma out of the centrifuge and to convey at least a portion of the separated red blood cells out of the centrifuge for collection, with a fluid including the buffy coat remaining in the centrifuge; execute a platelet resuspension stage comprising a first phase in which the centrifuge is deactivated and the pump system and the valve system cooperate to circulate the fluid in the centrifuge through the centrifuge to form a homogenous mixture, and a second phase in which the centrifuge operates to separate the homogenous mixture into a platelet concentrate and red blood cells; and execute a platelet harvest stage in which the pump system and the valve system cooperate to convey whole blood from the blood source or at least a portion of the collected red blood cells into the centrifuge to convey at least a portion of the platelet concentrate out of the centrifuge for collection.