I don't have the link handy, but recent research is showing the biggest gains in vertical are achieved when plyometrics routines immediately follow the leg strengthening work out. So hit the weights and then go right into plyometrics. It'll be a little wobbly at first so take it easy.
Link would be nice.
I could believe some of it as the nervous system is DEFINIETLY active afterwards...
But a full plyometrics workout? I don't know about that. If it's a partial plyometrics work with maybe one or two different exercise I could understand. That would make some sense if the muscles aren't too fatigued.