Drafted in the fifth round from FCS Alabama A&M in 2003, Robert Mathis emerged in Indianapolis as an underrated pass-rush specialist. His relentless energy and quickness off the edge challenged typical size expectations. Standing 6-foot-2 and weighing 245 pounds, Mathis progressed from a third-down specialist to a premier game disruptor, excelling in strip-sacks more than anyone else before or after him.

Teaming up with Dwight Freeney, Mathis helped form the premier edge-rushing tandem of the 2000s, generating non-stop backfield havoc that fueled the franchise's golden era. A cornerstone of the Super Bowl XLI championship squad, he was a five-time Pro Bowl selection (2008–2010, 2012, 2013) whose production spiked even higher when head coach Chuck Pagano shifted him to stand-up outside linebacker in 2012. That scheme change culminated in a historic 2013 campaign: Mathis earned First-Team AP All-Pro honors, won the inaugural Deacon Jones Award by leading the NFL with a career-high 19.5 sacks, and led the league with eight forced fumbles while finishing as the runner-up for AP Defensive Player of the Year.

After missing the entire 2014 season due to a torn Achilles tendon, Mathis demonstrated his signature resilience by returning for two final campaigns to close out his career. As the last remaining active player from the Super Bowl XLI championship roster, he played his final game in 2016, fittingly capping his legacy with a signature strip-sack against Jacksonville to pass Freeney on the all-time sack list. His unrivaled ability to swat the ball free left him as the NFL's all-time record holder for career forced fumbles (52) and strip-sacks (47). 

123.0 sacks, 538 combined tackles (408 solo, 130 assists), 108 tackles for loss, 141 quarterback hits, 52 forced fumbles.  In 2021, the team inducted Mathis into their Ring of Honor.