While this might be the biggest leap of faith among the four contenders, Justin March belongs in this conversation.
March was signed as an undrafted free agent last season to play inside linebacker after a solid four-year career at the University of Akron. He came to training camp and started turning heads immediately, to the point where Reid and his coaching staff were bringing him up unprompted in press conferences.
In the preseason, March had four tackles in the second half against the Arizona Cardinals, flying around the field. However, March tore the meniscus in his knee and was placed on injured reserve to recover and learn the playbook.
It would be an upset, but March might end up starting opposite Derrick Johnson. He was firing up the depth chart before being hurt last season. If he retained his explosiveness and can stay on the field, perhaps he overtakes Josh Mauga and becomes another impact player.
The sample size is admittedly very small, but March looked like a wunderkind in training camp and limited preseason action.