An apparatus to block an access port of a pump includes a cover having a distal end and a proximal end, wherein the distal end is configured to be received into the access port, an indexing device to prevent rotation of the cover with respect to the access port, a first component of an anti-rotation mechanism located upon the proximal end of the cover, a retainer configured to rotatably engage and abut the proximal end of the cover to resist removal of the cover from the access port, a key to engage the proximal end of the cover through a profiled keyway of the retainer, wherein the key comprises a second component of the anti-rotation mechanism, and at least one magnet to retain the key against the proximal end of the cover, wherein the profiled keyway is configured to restrict rotation of the key with respect to the retainer.