Tony Romo
America’s Team had massive hopes ahead of the 2015 season. Most fans agreed that they were desperately lucky to fall out of the playoffs the previous year. They had a great shot of making it through the weak NFC East. But then Tony Romo fractured his collarbone and they started 0-7.

Romo’s injury killed their season because they lost their starting quarterback. That’s not a position that any franchise wants to be in and it hurt the Cowboys badly. Things became even worse for them when Romo refractured his collarbone. It was a miserable year for Dallas and their star (via The Guardian).