A tissue puncture closure device includes a vessel locator and a sealing plug delivery member. The vessel locator includes an expandable member. The sealing plug delivery member includes a carrier tube, a sealing plug, and a locking member. The carrier tube includes a distal end and a side opening, the side opening extending proximally from the distal end along at least a portion of a length of the carrier tube to provide lateral insertion of the vessel locator into an interior of the carrier tube. The sealing plug includes a lumen and a slot extending from a distal end to a proximal end of the sealing plug, wherein the slot provides lateral access of the vessel locator into the lumen. The locking member is operable to retain the vessel locator within the sealing plug delivery member.
