Rupture of single adsorbed lipid vesicles is believed to occur via pore formation in the membrane. The latter process is related to the support-induced membrane strain. It includes membrane bending primarily near the rim of the vesicle-substrate contact area and tension distributed over the whole membrane. Herein, the relative role of these two factors is scrutinized from the perspectives of general theory and available experiments. The former factor is concluded to dominate. (C) 2015 Elsevier B.V. All rights reserved.