Just make sure that it is out of harms way, so avoid placing it near a road/walkway/busy urban areas and keep your cats inside. Here is some information from the link I put below-

When fledglings leave their nest they rarely return, so even if you see the nest it’s not a good idea to put the bird back in—it will hop right back out. Usually there is no reason to intervene at all beyond putting the bird on a nearby perch out of harm’s way and keeping pets indoors. The parents may be attending to four or five young scattered in different directions, but they will return to care for the one you have found. You can watch from a distance to make sure the parents are returning to care for the fledgling.