The man with the problem (original poster) made his first post so based on the info in the first post, did he give any indication that works for ups and has a sup to call?
And if he did work for ups, surely he would already know any potential solutions he could put into place .
Do you bother reading posts before you reply to them?
Even if he works in the center, the chance of getting it before Monday AM is pretty slim, but I have seen it done on a few rare occasions.
There should be a supervisor in the building for the Saturday operation. If you can find him and convince him that its a dire emergency, potentially could locate the trailer, cut the seal and look for the package. Depending upon where the trailer is staged and how full it is, this can be quite difficult as the trailer should be patterned parked to block access to the rear door and there may be 1500 packages loaded on top of the one being looked for.
A second unlikely option is to try the same thing when the building opens on Sunday night/Monday AM for the preload operation. If it's a full time preload it should open around 11 pm Sunday night. If it's a typical part time preload it probably opens around 4 am Monday.
There is a pretty good chance it could be intercepted in the center on Monday am, just before the truck leaves.
All three options would require the person to go to the center to find a willing supervisor or manager. The official answer from customer service is that it's not possible.