Juvenile Starling, injured?

Hello - I came out the garden about three hours ago to find what my Dad tells me is a young starling just standing on the stones, looking like it was having a rest. Unusually, it had made no effort to fly away when I opened the door. It hasn't made any calls since, made one aborted attempt to fly, before finding the tiniest space between a plant tub and the fence to sit.

Starlings have set up home in our the eaves of our roof as normal this year, I'm wondering if this juvenile has fallen, is too young to know what to do? Is three/four hours too long for it to be not injured and without food?

Reading a little seems to suggest that leaving it alone and checking frequently is the best course, is this right?

Thanks for any advice!