Colorado Avalanche center Nathan MacKinnon missed Tuesday’s 2-1 win over the Calgary Flames with an upper-body injury and was sent home, coach Jared Bednar said.

Nazem Kadri took MacKinnon’s spot on the Avs’ top line with Valeri Nichushkin and Mikko Rantanen as Colorado won the matchup of Western Conference division leaders.

Bednar didn’t specify MacKinnon’s injury to reporters but said his concern about it is “high.” MacKinnon was hurt in a third-period fight with Minnesota‘s Matt Dumba on Sunday.

Bednar said MacKinnon will get evaluated in Denver and that there’s no timeline yet for his return.

MacKinnon has 70 points this season (22 goals, 48 assists) for the Avalanche.

The Associated Press contributed to this report.