Should I intervene with a lost homing pigeon?

there’s been a pigeon in my garden since yesterday afternoon. It’s got rings on each of its legs but I can’t get close enough to read anything on them. It’s walking around on the ground but doesn’t seem able to fly. It’s currently hiding under a car. Having read other advice I left some food and water for it over night but it doesn’t seem to have touched the food. 

If it’s not flying should I assume it’s injured, or may it just be tired? I don’t want to cause it unnecessary stress by trying to capture it but I’m concerned about cats getting sight of it. Is it better to try to capture it so that it’s safe? Or give it a chance to recuperate and leave of its own accord?