Won't work. The WD Media player only uses USB drives as a source, not network drives. The wireless NAS only has network connections to PC's, no USB for connecting anything except for USB hard drives. You'll probably need to use a network media player like the D-Link DSM 320 instead of the WD HD Media Player in order to do what you want to do.
In fact, there's an unofficial firmware which allows wireless connections using certain usb wireless adapters: