The 1906–07 Manitoba Professional Hockey League (MPHL) season would see the 1906 MPHL champion Kenora Thistles challenge the Montreal Wanderers in a Stanley Cup challenge in January and win the MPHL championship, only to lose the Cup in a challenge in March.
The Winnipeg Hockey Club and Winnipeg Victorias left the league which now accepted professionals openly. The teams organized an amateur league.
Teams played ten games, except for Kenora, which played the Stanley Cup challenge. As a consequence, the standings were adjusted to account for the challenge.
After the Thistles won the Stanley Cup in Montreal, the team played exhibitions in Ottawa and Toronto. In the Ottawa game Billy McGimsie suffered a career-ending shoulder injury. At the time, it was not described as serious, only a "badly bruised and slightly dislocated shoulder". He played in the Thistles' next exhibition in Toronto on January 25. The team signed Fred Whitcroft to replace him. Kenora signed Alf Smith and Rat Westwick of Ottawa, whose season with the ECAHA was already over, for the final game of the season and the playoffs to play in place of future Hall of Famers Art Ross and Joe Hall who were back playing for Brandon.