When Dan Dierdorf saw something in terms of unfair labor practices, he said something, leading to groundbreaking decisions that accelerated the push for NFL players’ rights.

Soon after being selected by Arizona in the second round of the 1971 NFL Draft, the former Michigan all-American offensive lineman became the Cardinals’ player rep. Dierdorf’s voice was among the strongest during the 1974 preseason strike, which helped him convince nearly all of his veteran Arizona teammates to join the picket line.

As a witness to several unfair labor practices by the Cardinals front office, including intimidating tactics with rookie players in training camp and the denial of veterans’ right to communicate with rookies during the strike, Dierdorf provided testimony critical to the NFLPA winning a decision in 1976. The ruling also brought purpose to the week-long strike he helped the New England Patriots carry out in 1975.

Dierdorf’s impact was also felt on the field during his 13-year NFL career, leading to his induction into the Pro Football Hall of Fame in 1996 for his efforts as a player and union leader.