A flush syringe assembly comprising: a barrel including a side wall having an inside surface defining a chamber for retaining fluid, and outside surface, an open proximal end, a distal end including a distal wall having an aperture therethrough in fluid communication with the chamber; an elongate plunger rod disposed within the barrel, the elongate plunger rod comprising a distal end including a stopper slidably positioned in fluid-tight contact with the inside surface of the barrel; a cap comprising a passageway therethrough in fluid communication with the chamber, the cap including a distal end being releasably connectable to a vascular access device and a proximal end releasably attachable to the barrel; a valve comprising a plug positioned adjacent to the distal end of the barrel and in contact with the proximal end of the cap; characterized in that the flush syringe assembly further comprises a sleeve coaxial with the barrel and having a distal end and a proximal end, and an inside surface and an outside surface, the sleeve further comprising a handle adjacent to the proximal end of the sleeve; a disinfecting system comprising a hub connected to the distal end of the sleeve and having a distal face and a proximal face adjacent to the distal end of the cap; and a disinfectant carrier having a disinfectant in contact with the distal face of the hub; wherein the disinfectant carrier is fitted within a recess on the distal face of the hub, the sleeve covers the cap prior to use of the flush syringe assembly and until flushing of the vascular access device is complete, the disinfecting system further comprises a removable cover for protecting the disinfectant carrier prior to use, wherein during use, the sleeve causes a tip of the cap to press against the proximal face of the hub, forcing the hub to become disengaged from the distal end of the sleeve. a barrel including a side wall having an inside surface defining a chamber for retaining fluid, and outside surface, an open proximal end, a distal end including a distal wall having an aperture therethrough in fluid communication with the chamber; an elongate plunger rod disposed within the barrel, the elongate plunger rod comprising a distal end including a stopper slidably positioned in fluid-tight contact with the inside surface of the barrel; a cap comprising a passageway therethrough in fluid communication with the chamber, the cap including a distal end being releasably connectable to a vascular access device and a proximal end releasably attachable to the barrel; a valve comprising a plug positioned adjacent to the distal end of the barrel and in contact with the proximal end of the cap; characterized in that the flush syringe assembly further comprises a sleeve coaxial with the barrel and having a distal end and a proximal end, and an inside surface and an outside surface, the sleeve further comprising a handle adjacent to the proximal end of the sleeve; a disinfecting system comprising a hub connected to the distal end of the sleeve and having a distal face and a proximal face adjacent to the distal end of the cap; and a disinfectant carrier having a disinfectant in contact with the distal face of the hub; wherein the disinfectant carrier is fitted within a recess on the distal face of the hub, the sleeve covers the cap prior to use of the flush syringe assembly and until flushing of the vascular access device is complete, the disinfecting system further comprises a removable cover for protecting the disinfectant carrier prior to use, wherein during use, the sleeve causes a tip of the cap to press against the proximal face of the hub, forcing the hub to become disengaged from the distal end of the sleeve.