It's possible that it was just a mental thing, Sherrod adjusting to the speed of the game. Maybe you can't really simulate a speedy edge rusher in practice very well.
One thing that happens in practice is you keep lining up against the same few guys day after day. After a while you start to pick up on their tendencies.
Ring the bells that still can ring
Forget your perfect offering
There is a crack, a crack in everything
That's how the light gets in - Leonard Cohen