You got schooled already by
bkight13, but you didn't learn much.
Lee is above average athletically...even for the NFL and for his position.
A few Lee facts:
--He averaged 21.2 points, 9.1 rebounds and 3.2 assists as a senior in helping his school win a district title.
--In football, Lee rushed for 1,240 yards and 21 touchdowns while registering 95 tackles and four picks as a safety for an 11-1 squad his senior year.
(every good athlete does this in their high school playing days)
--He was athletic enough to be regarded as a first round talent by draft guru Mike Mayock
--He has been athletic enough to win NFL player of the month honors
(Mike Mayock? really, that is your argument? Next it will be Kiper? LOL
There are lots of guys who are simply predisposed to ACL injuries. I know--I'm one of them...and have had four ACL related surgeries.
I suspect a huge factor in his being injury prone: He's simply undersized. He played safety in high school and is really a bit of a tweener. Consider this: he's the same size as our old safety Roy Williams, but he's been playing deep in the middle of it....surrounded by 320 pounders and even running backs that are bigger than him. It becomes a simple issue of physics and pressure.
As per the OP's notion of using the bench more...I agree 100%.