I can't delete workspaces I no longer need (?)

Hi. I'm cleaning up workspaces, making improvemnts, etc. and now want to delete the old ones I no longer need/like. But when I pull down the menu for >window >workspaces I don't seem to have that option to "delete workspace" anymore. Only to edit or save a new one, reset, or save changes to current. Isn't that odd? Or what am I doing wrong here? Thanks for any tips...