First of all just because NFL guys are the best all-around athletes as some have said (and this may be true) doesn't mean this talent extends into the realm of distance running. Take a look at any jr high or high school PE class (I'll use mine as an example). Before I even started running I could kill my entire PE class on our PE XC course (1 mile), including all the multi-sport stars and supposed super athletes (and some of them were super athletes). I wasn't any Alan Webb either...at that time I doubt I could break 11:00.
Second, if you look at the annual high school lists, you will find that many 1:53-1:55 guys (which may be a reasonable guestimate of what a DB or WR could run) will barely break 10:00, especially if they were tending to be 400/800 types. The guy who holds my HS 800m record ran 1:55 in hs and 1:53 in college and had the body type of a distance runner (5'10 and 140-150lbs) and couldn't break 10:00 even though all he trained for was running.
I don't doubt that a number of NFLers could run under 10:00 if they stopped training for football, shed some muscle, and focused on the 2 mile. But I really doubt that many of them are suited for distance running. There are probably a few guys out there that would surprise you though.