There is no such thing as being too smart for the NFL. The Ivy League schools are all technically D1. Ryan Fitzpatrick, currently starting quarterback for the Tampa Bay Buccaneers, studied economics at Harvard: https://en.wikipedia.org/wiki/Ryan_Fitzpatrick. John Urschel was a guard for the Baltimore Ravens before leaving to pursue a PhD in math at MIT: https://www.washingtonpost.com/news/early-lead/wp/2017/07/27/at-age-26-ravens-john-urschel-retires-from-nfl-to-pursue-phd-in-math-at-mit/
But as you'll read in that article on John Urschel, playing football, particularly at the professional level, poses enormous risk of brain injury. If you're a strong student, consider what you'd want to be doing long-term. Playing in the NFL won't last forever, but a degree in mathematics can lead to jobs in finance, technology, consulting — really anything technical. Even within the NFL, it's the players at the very top making the most money and getting the most attention. NFL contracts also aren't guaranteed, and so even if you make it to the big time, the team can cut you and you won't get everything you were promised: https://www.oregonlive.com/nfl/index.ssf/2017/07/nfl_players_express_annual_sho.html.
Unless you are truly a legend at football, my advice to you would be to focus on academics and pursuing a career.