The two week lead up is huge!

"A review of the Patriots’ injury reports this season shows that four players had documented concussions, missed the game after sustaining the concussion, and then returned to action the following week."

http://www.espn.com/blog/new-england-patriots/post/_/id/4811002/why-two-week-timeframe-is-critical-for-gronks-chances-to-play-in-super-bowl