Duane Rupp was a player who definitely benefited from the NHL's decision to double its size through expansion in 1967.
After completing his final season of junior with the SJHL's Flin Flon Bombers, Rupp spent almost an entire decade in the minor leagues. In that time he played for 8 different teams, but only saw 9 games of NHL action with the Maple Leafs, most of those as a brief injury replacement. With the likes of Tim Horton, Allan Stanley, Carl Brewer and Bobby Baun leading the Leafs to multiple Stanley Cup championships, Rupp had little chance of cracking the line up.
He was considered much too slow to play in the big leagues. He was also considered to be too passive. He appeared to be a giant player, even though the was only 6'1" and 190lbs. The fans and coaches wanted him to be a mean son of a gun hitter and intimidator on the back line, but he had a long fuse and was not wired that way. When he was sufficiently provoked he could handle himself nicely, like the night he roughed up Bobby Orr, which only left fans and coaches longing for more.
But during his time in the minors Rupp became a very solid rearguard. Three times he was an AHL all star and he was a key member of a strong Rochester Americans team that won championships in the late 1960s.
When expansion came in 1967, Rupp found a job at the NHL level for the first time. He did not disappoint. Though he scored just 1 goal and 9 points, the 29 year old rookie was a very steady contributor.
The Minnesota North Stars claimed Rupp in the inter league draft prior to the 1968-69 season but by January traded him to the Pittsburgh Penguins in exchange for Leo Boivin.
In Pittsburgh Rupp enjoyed his best NHL playing days. A large reason for that was his coach. Leonard "Red" Kelly was one of the greatest defensemen the game has ever or will ever see, and he helped out Rupp with his game even more so. He even became the first defenseman in team history to score a hat trick.
Regardless of reliable play, he became a favorite of the Penguins boo-birds, due to his perceived lack of physicality. After the 1972-73 season Rupp was demoted to the minors, as the Pens looked to bring some youth in on their blueline. After one all star year with AHL Hershey Rupp returned to major pro hockey by signing with the Vancouver Blazers of the WHA. He would also spend a year in Calgary with the WHA.
In 1976-77 Rupp returned to the scene of his best days of pro hockey - Rochester New York. Rupp played in 41 games to round out his lengthy professional hockey career.