I took a chance on a Division I PG with a durability of 3. Redshirted the first year.

Question is: Would he be a viable back-up or is he destined to be injured the entire season? I have left the option to cut and replace this season but am leaning to trying for one season to the see the result.

Any experience or advice from the crowd?

I don't think he'll have any more chance of injury than another guy. I had a guy with an 8 and he never missed a game in 4 seasons.

However, if he does get hurt, the Health number will drop much lower than for a guy with a higher Durability number. Meaning it will take longer for him to recover from that injury.
Example, a guy with a high DUR may sprain an ankle and his Health rating may drop to 85. The same injury to this guy might see the Health drop to 50-60 range, which could cause him to miss a couple games.

my experience is DU is unimportant. i could be wrong , but i think it does not affect frequency of injuries, but does affect how quickly an injured player recovers. i feel like i only see one singificant injury every 20-25 seasons. cant even remember the last one.

Durability is pretty much a throwaway for me -- in order for it to matter you have to first get triggered for an injury (a rare occurrence), the player in question has to actually be on the floor (not a given), he has to be the one assigned to receive the injury (DUR might play a role here...not sure), it would have to be a severe injury (again, not a given, though again DUR might increase the odds a bit). It's biggest impact is that, once injured, the guy will regain health slower than a higher DUR player.

But I play the single digit DUR roulette wheel all the time and don't even think twice about it. As old warrior said, I've had guys with DUR ratings so low you'd swear they'd injure themselves tying their shoelaces and they ended up being 4-year starters never missing a minute.

The only time I had an issue with low durability was when I ran an uptempo offense every game. My low durability player twice got injured in a season....may have just been dumb luck though.

It's useless. Injuries are totally random and major ones so rare that I would never consider durability as a factor in evaluating a player.