A removable cap for a cardiovascular cannula has a sleeve section with an inner surface adapted to receive a connector end of the cannula. The cap has a top section closing a closed end of the sleeve section. A pull tab extends radially from an open end of the sleeve section. A pair of tear seams are sunk into the sleeve section and the top section defining a tear strip in the cap. The sleeve section includes a segmented snap ring protruding radially inward on the inner surface of the sleeve section except at a pair of gaps coinciding with the pair of tear seams. The top section includes a seal cylinder projecting concentrically from the top section to seal against an inside surface of the cannula connector end.