Armstrong announced his intention to retire as a player following the championship but changed his mind and returned for another season. The Maple Leafs placed him on their protected list for the 1967 Expansion Draft, and he remained with Toronto. He played in his seventh All-Star Game in 1968 and finished the season with 34 points. Retiring following the season before changing his mind became an annual event for Armstrong as he announced his intention to leave the game in five straight years. He remained a consistent scorer for Toronto, recording 27, 28 and 25 points in his following three seasons. He finally ended his playing career after the 1970–71 season to take an office position in the Maple Leafs., and also he finished his career with two hundred and ninety-six goals, four goals away from obtaining three hundred. At the time of his retirement, Armstrong was second to Dit Clapper for the longest tenure as a team captain in NHL history.