Having kept and raised a variety of wild bird youngsters, although it's true that depending on how they are raised, they are often imprinted on humans and have difficulties in being successfully released, I'd say that since house sparrows along with European starlings are typically listed as invasive and in the US not protected by our Migratory Bird Act.(in most states).
Both house sparrows and starlings can be very interesting, if not an unusual pet birds.
Keep in mind though that if it's determined that he is to be a pet and not released, it's important to keep him quarantined at least for the time we would do for new budgies (perhaps a bit longer). Additionally, keep in mind that just like a new budgie, if after quarantine, a relationship doesn't develop, they may need to live in separate cages.
Both of these species are very social and the personality of each bird would determine
how/if they can live together. Good luck.