start of the 1921–22 NHL season, Hamilton traded him to the Montreal Canadiens for Harry Mummery and Amos Arbour. On the Canadiens, Cleghorn was reunited with his brother, Odie. In his first season with his new team, he scored 17 goals and had nine assists in 24 games. Towards the end of the season, he was named captain of the team. The Canadiens made the Stanley Cup playoffs every year over the next three seasons. He played alongside Billy Coutu, and the pair established a reputation as one of the most feared defensive pairs in the league. On Jan. 14, 1922, Sprague and Odie each scored 4 goals in a 10–6 victory for the Montreal Canadiens over the Hamilton Tigers. In a 1923 playoff series, against his former team, the Ottawa Senators (whom he had grown to despise), Cleghorn struck Senators defenceman Lionel Hitchman in the head with his stick. He was charged with aggravated assault, found guilty and fined $50. The incident enraged Canadiens owner, Leo Dandurand, who suspended him from the roster for the remainder of the playoffs. In another incident with the Senators in 1922, he initiated a brawl during which he injured three players, Eddie Gerard, Frank Nighbor and Cy Denneny. The Ottawa management attempted to have him expelled from the league, and a referee described him as a "disgrace to the game". In 1923–24, the Canadiens won their first Stanley Cup in the NHL. It was the third championship of Cleghorn's career. After the following season, Montreal sold him to the Boston Bruins for $5000. He played three seasons with the Bruins and acted as their unofficial captain. In his final season with the Bruins, 1927–28, he also served as an assistant coach. During his time in Boston, he served as a veteran presence on the team and as a mentor to future Hall of Fame defenceman Eddie Shore. Post-retirement career After his retirement as a player, Cleghorn took to coaching. He joined the Newark Bulldogs of the Canadian-American Hockey League (CAHL) as a player-manager from 1928 to 1929. During this time he acquired his former Montreal teammate, Billy Coutu, to serve as his defensive partner. A newspaper at the time stated that the move "reunit[ed] the most formidable defence that ever played hockey". In the 1930–31 season, he coached the CAHL's Providence Reds, and in 1931–32 he was named head coach of the NHL's