Trustee Substitution? Can still buy house from original owners?

[Ivan Sosa]

I been trying to buy house at pre-foreclosure and I been using the county recorders office to get information. Now I saw a house that was set for auction on a certain date, the day came and went.  The house still going to be auctioned out at a different day months after the original auction date, but I also noticed that there is a substitution of trustee paperwork that has been recorded. Does this means the original homeowners are not longer in charge of the house? Am I wasting my time by trying to track down the homeowners and making them an offer? I'm sure the role of the new trustee or whose interest he holds but I'm pretty sure is the bank's. I always believe that the homeowners had until the day the house actually gets auctioned out to do something about it like selling the property. Any information is highly appreciated.