Any rescue should be done with the best intentions for the animal. It's possible to see no visible sign of problems, but end up with an animal that starts wheezing a month later. So if you decide to take in this animal, be prepared for the possiblity.

In general though, I'd look for mites and listen for any wheezing. Make sure the vent in clean and that the mouth is free from any discharge as well.

Best of luck, and let us know what you decide.