Three-time All-Pro safety Tyrann Mathieu announced in a post on his Instagram page that he is retiring from the NFL. The 33-year-old defensive back was entering his fourth season with the New Orleans Saints but won't step onto the field this year.

After Tyrann Mathieu announced his retirement, Chiefs QB Patrick Mahomes sent some kind words to his former teammate.

In a surprising announcement, Tyrann Mathieu said he’s retiring from the NFL after 12 seasons. Mathieu, 33, last year completed his third season with the New Orleans Saints, his hometown team. He also played for the Arizona Cardinals, but the best years of his career were spent in Kansas City.