Yeah, maybe somebody who's followed football before. Peter King wrote a story about him and his only exposure to the game was playing the Madden video game. He didn't know what a "crash blitz", "zone blitz" "cover 3" were when he was playing the game, he said it just sounded like a good play.
If you've never played or watched a lot of football, it's an extremely hard game to pick up. Think of all the things he has to learn--- plays, formations, penalties, rules, tackling form, technique, leverage, play-action, angles, coverage zones, etc.
I'm not saying he's not capable of learning all of that, but to say that 13 weeks should be "plenty" of time to learn LB at the professional level is crazy. Not to mention, I think there's certain CBA rules about practice squad contact and hitting.