An aerosol-generating article including an aerosol-generating rod for producing an inhalable aerosol upon heating is provided, the rod including: a first aerosol-generating segment including a first aerosol-generating substrate, the first aerosol-generating substrate including a tobacco material and an aerosol former; a second aerosol-generating segment at a location upstream of the first aerosol-generating segment; and a wrapper circumscribing at least the first aerosol-generating segment and the second aerosol-generating segment, the second aerosol-generating segment including a plug of a porous substrate, and at least a core portion of the plug including an aerosol-generating medium or a flavourant or both. An aerosol-generating system including a heating device and the aerosol-generating article is also provided.