Sorry, but there is absolutely no correlation between a player being on the Madden cover and having a crappy year. Sometimes it happens, other times it doesn't. I seem to remember Drew Brees gracing the cover in 2010, and then making it through the whole season uninjured and leading the Saints to the playoffs. Larry Fitzgerald shared the cover with Troy Polamalu the year after and nothing happened to him, and Polamalu, for that matter, played in 14 out of 16 games.
This whole idea of a player being cursed because they're on the cover of Madden is a joke.