Cooper takes in the look of the alleyway in a moment. There's only two places to go once inside of it: back or forward. The werewolf has made an error that will cost him his life. "You take the front. I'll block the exit. We can corral him in." Just because the wolves were weakened by the Blood Moon doesn't mean that they've gone stupid as well. If a fight can't be won, then logically the next step will be to run.

Cooper goes back the way he originally came, up the side of the nearest building and onto a rooftop that overlooks the alley. He drops down at the exit, creating enough of a stir to get the wolf's attention so that Liam can move into position.