Matt Bowen at National Football Post breaks down the film on all the things Green Bay Packers CB Sam Shields did wrong on the fourth quarter touchdown pass thrown to Steelers WR Mike Wallace. He goes through four points where he failed to press at the line, slide his feet, play to his help, and recover. The first comment addressed my first thought - maybe he couldn't press at the line because he had an injured shoulder?
Bowen dismisses this thought in the comments because Shields isn't seen even attempting to jam. My next thought was that his injured shoulder would have discouraged him from even attempting one, but that excuse is just a different kind of mental lapse. Plus Bowen knows more about playing defensive back in the NFL then I ever will. It's too bad we don't know how badly his shoulder was injured was because the Packers don't have to disclose an injury report after the season.
Another possible rookie mistake could have been that Shields was confused about the defensive assignment. He had missed nearly the entire third quarter, and defensive coordinator Dom Capers scrapped the defensive game plan in the second half by going away from man coverage with more zone. Instead of playing his usual press coverage, Shields might have had a mental lapse and found himself halfway between press and zone. That's still a mental mistake, but it was a rough game for the rookie who might have made a rookie mistake.
The Super Bowl wasn't his best game, but I'm not letting it take away from what was an amazing rookie season.