Keane, 31, has now alerted Villa boss Alex McLeish to the prospect of a permanent switch.
The Republic of Ireland skipper said: "Villa is a great club but it was my choice to go to the States.
"When I go back to LA, it could be totally different. At this moment in time I can't tell what will happen. It's a case of watch this space.
"But people have seen over the years with the clubs I've been at, how quickly I leave if I don't think I fit in."