Clay Matthews Sr., who was the patriarch of one of the NFL's most successful family trees, died on Thursday night. He was 88.
The official cause of death was not immediately disclosed for Matthews, who played both on the offensive line and defensive end for the San Francisco 49ers during the 1950s.
Matthews recorded one interception while playing 45 games over four seasons (1950, 1953-55) with San Francisco.
His sons, Bruce and Clay Jr., each enjoyed distinguished 19-year NFL careers, with the former being inducted into the Hall of Fame in 2007 while the latter was a semifinalist in the 2017 class.
Bruce and Clay Jr. each have sons that played in the league. Atlanta Falcons left tackle Jake Matthews and former Tennessee Titans, Washington Redskins and Carolina Panthers offensive lineman Kevin Matthews are Bruce's sons. Green Bay Packers linebacker Clay Matthews III and former Philadelphia Eagles and Minnesota Vikings linebacker Casey Matthews are Clay's kids.
Mike Matthews, who is also Bruce's son, is an undrafted free agent who recently signed a futures contract with the Pittsburgh Steelers.