Here's the thing, TJ McDonald is an excellent football player, and he'll be fresh and uninjured when he is allowed to play. While he may not be our ideal FS, I'm very very confident that he'll be dramatically better at everything than we've seen from Nate Allen. McDonald will put genuine fear into receivers, stuff the run game, allow Jones to freelance more, and he has enough recovery speed to be effective in the FS role.
I'm excited to get him back in the team, because he's simply one of those guys the offense has to keep tabs on at all times. He can shut down the run game, he can scare deep threats so much they don't catch the ball. He is going to make less mental mistakes than Nate Allen has. And, TJ McDonald can tackle. That's not meant as a joke ... tackling is becoming a real problem in today's NFL where the collective bargaining agreement prevents padded practices etc., and tackling simply isn't practiced nearly enough.