Pittsburgh Steelers assistant coach John Mitchell has confirmed his retirement after a 29-year stint with the organisation.
Mitchell, the first African-American football player at the University of Alabama who won two Super Bowls as an NFL assistant, announced his retirement on Wednesday.
He had been with the Steelers since 1994 after being hired by Bill Cowher and remained on their staff ever since.
The 71-year-old was part of Pittsburgh's last two championship teams, one in 2005 under Cowher and the most recent coming in 2008 under Mike Tomlin.
"I'm not sure that I can offer sufficient praise and admiration for Mitch, as both a man and football coach," Tomlin said in a team statement.
"Mitch has been a central figure in the success of the Pittsburgh Steelers for nearly three decades. He has coached some of the best players in this franchise's illustrious history, and each one of them, to a man, would tell you their success was a direct result of not only Mitch's coaching acumen, but also his mentorship, leadership and character."
Mitchell spent a total of 50 years as a coach, a career which began at alma mater Alabama in 1973 under the legendary Bear Bryant.
The Crimson Tide won a national title in 1973 with Mitchell working as the team's defensive line coach.
He would later have coaching stops at Arkansas, Temple and LSU as well as the USFL's Birmingham Stallions before a three-year run as the Cleveland Browns' defensive line coach under Bill Belichick from 1991-93.
Mitchell's greatest notoriety, though, came in 1971 when he and running back Wilbur Jackson became the first Black players at the storied Alabama programme. Mitchell was a two-time All-Southeastern Conference selection as a defensive end for the Crimson Tide and earned All-America honours in 1972.
"When you consider his path, as both a player and coach, Mitch created opportunities in football for young Black men that quite honestly, didn't previously exist," Steelers president Art Rooney II said.
"He has left an imprint on this franchise, and the sport and culture of football, that continue well beyond his retirement."