So we found her this afternoon wild eyed hiding under the deck of a secondary building on the property where she sometimes likes to sleep. She is a gray tuxedo cat and her little white chest was all bloody. She won't come out or respond to me at all, not even a meow

I broke off part of the lattice around the deck and pushed in as far as I could some crunchies, tuna and milk and left her alone. Ten or so minutes later she came out from under the deck licking her chops but when I went towards her she ran under my car and then under the deck of the house.
She's feral cat that adopted us so she's really a wild cat and now that she injured she's not letting me near her.
I don't know what to do, I don't know if we should trap her and bring her to the vet or just wait and see what happens. I really want see the wound and make sure there's no infection but I don't want to betray her by luring her into a trap.