I think it's too young to identify, but there is some trash in the nest (appears to be pieces of a tarp in there), so you might be right about it being an invasive sparrow (House Sparrow, specifically). If you left it where it was (I hope you did), then you can watch to see what species the parents are. Should probably get a photo to be completely certain.
- Bird Nut #1
(with the help of Bird Nut #2 on occasion)