The main topic across the NFL this week has been the start of training camp for many teams, with the Houston Texans kicking off their camp on July 23. Former Texans safety Tyrann Mathieu was one of these players.

Tyrann Mathieu isn't completely closing the door on a return to the NFL, but for now, the former Super Bowl champion and three-time first-team All-Pro remains confident in his decision after announcing his retirement Tuesday.

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.