By default, VMWare Player saves any VM you create to your documents folder and there doesn’t appear to be a way to change that.
However, there is.
Open up the following file in your favorite text editor:
Add in the following line, changing the path to your desired location:
prefvmx.defaultvmpath = "D:\Virtual Machines"
Save, restart VMWare Player, and your new location should work when creating a new VM.