Unger set an NHL record by playing 914 consecutive games in the regular season between February 24, 1968, and December 21, 1979, doing so with four teams: the Toronto Maple Leafs, Detroit Red Wings, St. Louis Blues and Atlanta Flames.

[1] Unger passed Andy Hebenton, who had the record of 630 consecutive games played that had stood since the 1963-64 NHL season.

Unger's streak came to an end after Flames' coach Al MacNeil benched him on December 21, 1979 (the only game he would miss that season).

He was part of a six-player blockbuster transaction in which he was traded along with Frank Mahovlich and Pete Stemkowski from the Maple Leafs to the Red Wings for Norm Ullman, Paul Henderson and Floyd Smith on March 4, 1968.

The Maple Leafs and Red Wings were in fifth and sixth place respectively at the bottom of the East Division standings at the time of the deal.