I'd think any of the top 200 player's who run for a living (play baseline tennis) can run a mile under mid 5's, but few would get into the highest 4's because they don't specialize in running.
For Beernutz, I never was a long distance runner, so higher 5's the best, in college. CC class had us running 6 miles for the gym period of one hour. I always finished and took a shower before hustling to the next class. As you know, periods are on hour total.