He was nicknamed "The Roadrunner" due to his small size and blazing speed, which he credited to longer blades on his skates.

[2] Cournoyer made his NHL debut in 1963 with the Montreal Canadiens and earned a full-time spot with the club in 1964 after just seven games with the American Hockey League's Quebec Aces.

[3] Cournoyer was initially regarded by Canadiens head coach Toe Blake as a defensive liability and undeserving of a regular shift, though he was still frequently used on the power play.

[2] That changed after Blake's departure following the Canadiens' 1968 Stanley Cup Championship, when incoming coach Claude Ruel granted Cournoyer a full-time shift.

[3] Cournoyer was named captain of the Canadiens in 1975 following the retirement of Henri Richard, pushing him to play harder in his new leadership role.

The speedy Cournoyer's ability to stay true to his form in his older age was a favourite topic of discussion of the Montreal fans and hockey media, however, and he did slow down due to a disc in his back that was pressing on a nerve and causing him great pain.