Conrad Dobler, a three-time Pro Bowler, died Monday at the age of 72, the Arizona Cardinals confirmed.

«Our hearts go out to Conrad Dobler’s family, friends and former teammates,» he posted on social media.

Dobler was a key member of the «Cardiac Cards» of the then-St. Louis Cardinals from 1972 to 1977, where he was also named a second-team All-Pro. Dobler played in the trenches at left and right guard under Don Coryell, who was posthumously inducted into the Pro Football Hall of Fame on Thursday.

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Conrad Dobler #66 of the St. Louis Cardinals watches the action from the sidelines during an NFL football game circa 1977. Dobler played for the Cardinals from 1972 to 1977. (Focus on Sport/Getty Images)

«He was the kind of tough, physical, ferocious player that you love to line up with as a teammate and hate to line up with as an opponent. On the field, Conrad was a huge reason for the success of Cardiac Cards of the 1970,» said the Cardinals owner Michael Bidwill in a statement.

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Dobler spent six seasons with the Cardinals before playing for the New Orleans Saints and Buffalo Bills before his retirement in 1981. He played in 129 career games, starting all but four.

But many of those who remember Dobler think of things that certainly wouldn’t fly in today’s league.

Jethro Pugh #75 of the Dallas Cowboys rushes against Conrad Dobler #66 of the St. Louis Cardinals during an NFL football game on December 3, 1972 at Busch Stadium in St. Louis, Missouri.  Pugh played for the Cowboys from 1965 to 1978.

Jethro Pugh #75 of the Dallas Cowboys rushes against Conrad Dobler #66 of the St. Louis Cardinals during an NFL football game on December 3, 1972 at Busch Stadium in St. Louis, Missouri. Pugh played for the Cowboys from 1965 to 1978. (Focus on Sport/Getty Images)

Dobler was known for using any means necessary to block his quarterback and running back, and these tactics were violations of league rules. That is why some consider him the dirtiest player in history, as he would have received multiple expulsions in today’s game.

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Dobler also enjoyed getting into the heads of defensive linemen, visibly confronting them between plays, including «Mean» Joe Greene.

Conrad Dobler #66 of the St. Louis Cardinals watches the action from the sidelines during an NFL football game circa 1977. Dobler played for the Cardinals from 1972 to 1977.

Conrad Dobler #66 of the St. Louis Cardinals watches the action from the sidelines during an NFL football game circa 1977. Dobler played for the Cardinals from 1972 to 1977. (Focus on Sport/Getty Images)

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The Cardinals selected Dobler in the fifth round of the 192nd NFL Draft out of Wyoming.