Indianapolis Colts owner Jim Irsay commented on the news on Twitter, calling him "One of the game's most legendary non-Hall-of-Famers."
Curtis played fullback at Duke University but switched to linebacker during his NFL career that started when the Baltimore Colts selected him with the No. 14 overall pick of the 1965 draft. He played 11 seasons for Baltimore and was a four-time Pro Bowler and two-time All-Pro selection during that time.
Mike Wells of ESPN noted his key interception in the fourth quarter of the Colts' Super Bowl V victory set up the game-winning field goal to cap off the 1970 campaign.
In all, he appeared in 166 NFL games with 131 starts and finished with 25 interceptions and nine fumble recoveries.