A hawk will attack a rooster in a heartbeat. I had a large White Rock rooster 'sound the alarm' a few years back and saw all my chickens running for cover in the backyard. I was heading outside to see what was going on and just as I was walking out the back of the garage I observed a hawk fly down out of my weeping willow tree and attack my rooster. I ran out there in the nick of time and scared the hawk off. My rooster jumped up at the hawk but the hawk punctered his comb with either a claw or it's beak...it was difficult to tell which because it happened so fast. My rooster's comb was bleeding from the puncture so I caught the rooster and returned to the garage where I have my emergency 'chicken kit.' I cleansed the wound with betadine, and applied pressure to the puncture to stop the bleeding with gauze. About 10 minutes later the bleeding had stopped, I applied neosporin to it and that did the job. the wound healed nicely and they hawk never returned. I guess I scared him off convincingly. A rooster is not "chicken." Yes, they'll run for cover, but they will die to protect their hens from hawks. If I were you, I'd continue to make sure someone is outside with your chickens when they're free ranging.
