He served as a scout for the Quebec Nordiques, as an assistant general manager of the Maple Leafs and for part of the 1988–89 NHL season as Toronto's head coach.

The younger Armstrong developed a passion for hockey but was a poor skater, which his father believed was a consequence of a case of spinal meningitis George suffered at the age of six.

[4] While attending Sudbury High School, Armstrong played on the hockey team with Red McCarthy and Tim Horton.

Inspired by a newspaper advertisement offering tryouts with the Copper Cliff Redmen of the Northern Ontario Junior Hockey Association (NOJHA), Armstrong convinced Horton and McCarthy to join him in trying out.

[5] He recorded six goals and five assists in nine games and caught the attention of scouts for the National Hockey League (NHL)'s Toronto Maple Leafs who added him to their protected list.

[5] The Maple Leafs placed Armstrong on the Stratford Kroehlers in the Ontario Hockey Association (OHA) junior division for the 1947–48 season.

While visiting the Stoney Reserve in Alberta with the Marlboros, the locals presented Armstrong with a ceremonial headdress and called him "Big Chief Shoot the Puck" owing to his own Native heritage.

Upon turning professional in 1950–51, Armstrong was assigned to Toronto's American Hockey League (AHL) affiliate, the Pittsburgh Hornets.

[9] Despite being hampered by hand and wrist injuries suffered in fights, Armstrong was the AHL's leading goal scorer and stood second in points by mid-season in 1951–52.

[9] Though he missed the start of the 1952–53 season due to a separated shoulder, Armstrong earned a permanent spot on the Maple Leafs' roster.

[7] The Maple Leafs named Armstrong the team's captain in 1957–58 as he succeeded Ted Kennedy and Jim Thomson who served as co-captains the season before.

[7] He recorded four assists in the playoffs as the Maple Leafs reached the 1959 Stanley Cup Finals, but lost to the Montreal Canadiens.

The Maple Leafs nonetheless eliminated the Black Hawks in six games to set up the 1967 Stanley Cup Finals against Montreal.

The Canadiens were so confident of victory that a display area for the Stanley Cup had been set up at the Quebec pavilion at Expo 67 in Montreal prior to the series' start.

[7] 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.

In 1977, Armstrong's name circulated as a possible successor to Maple Leafs coach Red Kelly when the latter was fired by the team.

His decision resulted in animosity from within the organization and subsequently led to his resignation as coach of the Marlboros that season to accept a scouting post with the Quebec Nordiques.

[31] Some 10 years later, Armstrong returned to the Maple Leafs organization in the dual capacities of assistant general manager and scout.

The Maple Leafs finished with 17 wins in 47 Armstrong's games coached, falling just short of the fourth and final playoff berth in the Norris Division.

[33] The Toronto Maple Leafs described Armstrong as being a "consistent, durable and hardworking" player throughout his 21-season career that spanned parts of four decades.

[3][38] Armstrong was a resident in Leaside, a neighbourhood in Toronto, for more than 55 years and often spent time with his family bike riding throughout the area.

[41] She joined Kelly Paton's coaching staff with the Western Mustangs women's ice hockey program in the autumn of 2016.

[1] Armstrong was recognized by the NHL for his charitable efforts in 1969 when he was named the inaugural recipient of the Charlie Conacher Humanitarian Award.