Summary:
- The article discusses Colorado Avalanche star Nathan MacKinnon training with Buffalo Sabres forward Casey Mittelstadt during the offseason.
- MacKinnon and Mittelstadt have been training together in Denver, focusing on improving their skills and preparing for the upcoming NHL season.
- The article highlights the camaraderie and competitive nature of the two players as they push each other to get better, even though they play for different teams.