He is close to back in the sense that a 28:06 is worth 13:30s (assuming a 30 second slowdown or so from a 5000m) and his pr in college as a freshman, the AJr, was 13:25. Variance from 5000m to 10000m differs from athlete to athlete, but consider some pr's:
Farah 12:53/26:46(?)=13:23/5k. 30 second slowdown (of course, he could have run a faster 5 and 10 with the right pacing).
Rupp 12:58/26:44=13:22/5k. 24 second slowdown.
Bekele 12:37/26:17=13:08/5k 31 second slowdown. Bekele could probably have run 26:10 or better with pacing to 20:00 or so.
As for the other guy above, I used to believe that if you are injury-prone, you'll never get over that, but it is often the question of the right exercises. I used to get injured every week or two in high school and college, almost never getting in any good block of training, even on very limited mileage, 20-40/week. But in my forties, I've been able to run well over 100 mpw with workouts fairly consistently because of a series of injury prevention exercises I've come across. Many of those would work with the pros as well.