Walker officially announced his retirement from the NFL on Tuesday, Jim Wyatt of the Titans' official site reports.
Walker, who hasn't played in an NFL game since 2019, retires as a three-time Pro Bowler. He'll be best remembered for his time with the Titans from 2013 through 2019, which was highlighted by a career-best 2015 campaign in which he logged a 94-1,088-6 receiving line on 133 targets.