His dad, Jack, won two Stanley Cups with Ottawa in the 1920s. Fleming was part of the Toronto Maple Leafs championship teams in 1949 and 1951.
The Montreal-born Fleming was already a hockey hero in Toronto long before joining the Leafs. He, playing alongside Red Kelly (who played junior as a forward), was the St. Mike's Majors leading scorer in the 1947 playoff run which ended with the Memorial Cup as Canada's junior champions.
Though he would spend his first pro-season almost entirely in the minor leagues, MacKell did start the season with the Leafs. Believe it or not, his first NHL game was the NHL all star game!
"In those days the Stanley Cup champions played an All Star team just before the season began. The Leafs were the champions. I seemed to have made the team at their training campand they used me in the All Star game," explained MacKell, who at the age of 18 years, 5 months, and 13 days, remains the youngest player to ever play in a NHL all star game.
"They had all the players at a luncheon the day of the game. I walked in and couldn't believe the guys who were in the room. There was Milt Schmidt and Rocket Richard and Ted Lindsay, Doug Bentley, Bill Durnan. You name it, they were there. I was scared to death!"
So scared, that he ran away from the luncheon!
"Hap Day was the Toronto coach. I told him I didn't belong. He said I had to stay. I did, for a little while. But I felt so out of place I sneaked out and took a streetcar home. I ate my lunch at home. Then I got back on the streetcar and went to the Gardens for the game. I thought Day would be mad at me, but he didn't say anything. Maybe he didn't miss me at the lunch."
Despite the promising start, MacKell would be in and out of the Leafs lineup until 1951. Of course those were the days where the Leafs were the league's power house, regularly winning Stanley Cups. MacKell would spend a lot of time in the AHL with Pittsburgh. When he was called upon by the Leafs he was expected to be a defensive-minded winger with rugged intentions. He was considered by many to be the fastest skater in the league when he played, despite a bowlegged stance.
MacKell stood just 5'8" and weighed about 175 lbs, which was small even back in those old days. He learned early on he had to stand his ground.
"There was a lot of intimidation if you weren't big. If you weren't a rough, tough player, you could never show that you didn't like the rough stuff or they would run you out of the league."
In the 1951-52 season MacKell was traded to Boston where he found a home for nearly a decade. He became an importantpart of the Bruins attack, as well as a specialty teams specialist. He was a regular on both the power play and penalty kill units, thanks to his speed. He was also noted for scoring goals from the side of the net.
The Bruins were not a great team in the 1950s, as that decade was dominated first by Detroit and then by Montreal.
"We were a good team in Boston. Not a lot of stars, but a good spirit on the team. The guys played together."
MacKell, who teamed nicely with Don McKenney, was arguably the Bruins best player. In 1953 he made the NHL First All Star team. He was a strong playoff performer, never more so than in 1968 when his 19 points in 12 games led the entire NHL in post-season scoring. His performance in that memorable Stanley Cup showdown with Montreal would have been one for the ages had the Bruins somehow upset the mighty Canadiens.
By the turn of the decade, MacKell found himself farmed out to the Quebec Aces of the AHL thanks to a dispute with Bruins management.
"The Bruins and I had kind of a falling out. They thought they had better younger players to bring in. The Bruins themseles didn't do very much after I left, either. They went downhill pretty fast. They could never beat anybody. When I was with them we never missed the playoffs except the year I had a bad knee," he said.
"They sold my contract to Quebec," he recalled. "I went to the Quebec Aces as a playing coach. That was a big mistake. It didn't work out at all."
MacKell decided to drop hockey after that sour ending, opting to go to work for Dow Brewerey in Montreal. He later moved to the car sales business.
For the record, Fleming MacKell played parts of 13 seasons in the National Hockey League with the Toronto Maple Leafs and Boston Bruins. In 745 regular season and playoff games he had 171 goals and 261 assists for 432 points.