A blood pump (1) comprises a pump section (2) and a flow cannula (3). A proximal end portion (14) of the flow cannula (3) is connected to the pump section (2) such that blood can enter the blood flow inlet (11), and a distal end portion (13) of the flow cannula (3) includes at least one blood flow-through opening (16) for blood to enter the flow cannula (3). The distal end portion (13) comprises an enlarged diameter portion (15), with at least a major portion of the blood flow-through opening (16) being disposed in the enlarged diameter portion (15). The blood pump (1) further comprises a sleeve (4) overlapping the enlarged diameter portion (15). The sleeve (4) has a structure that prevents its distal end (42) from bending radially inwards into the blood flow-through openings (16).
