Possible injured blackbird


On Friday morning a blackbird flew into and hit the bedroom window. It seemed to recover quickly and ran off up the garden. The problem is I don't think it's left the garden since. I'm wondering if it's hurt it's wing as it tried to jump up to the bird bath, but it couldn't make it up there. It was in the garden Friday & Saturday and it's been here all day today. I contacted a local wildlife rescue, and they have told me to leave it as their wings are too small to treat. My problem is it can't get out of the garden as its all enclosed, and there isn't really anywhere for it to hide safely. I did try to catch it before I contacted the rescue, but I can't get near it.

I've put some water on the floor and I've scattered food on the floor too, but what do I do?