We just did a 5k time trial for our soccer team. Everyone ran over 19 minutes except 1 guy who killed everyone running 15:25. He's never run track before and has never timed himself for runs (we ran 10k once a week for soccer training).
I don't know much about distance running as I only ran the 400m in high school but this seems really fast. He smashed the 2nd place guy by like 3 laps. I told him after he should think about training seriously for track but he doesn't believe he's even close to pro as the world best guys are all 12 minutes but I think he could easily get down to 13 or so with full time training. He's 24.