Former Ottawa Senator Mark Kastelic reminded fans on Saturday night why he’s a player most NHL players don't look forward to tangling with. Now with the Boston Bruins, Kastelic got into a brawl on Saturday night with Detroit Red Wings star defenseman Moritz Seider, and the results were predictable.
This was only Seider's second NHL fight, and it represented a huge jump in skill and weight class compared to his first career scrap. According to HockeyFights.com, that one was against Nashville Predators' star forward Filip Forsberg two years ago.
The incident came in the final seconds of the first period. Kastelic collided hard with Seider in the Detroit corner. The two began with some squawking and shoving, but them things quickly escalated from there.
Moritz Seider vs Mark Kastelic Nov 29, 2025Moritz Seider vs Mark Kastelic from the Detroit Red Wings at Boston Bruins game on Nov 29, 2025. via https://www.hockeyfights.comIt was a little surprising to see the Wings' prized defenseman being allowed to freely square off against one of the league’s tougher hombres with zero intervention from teammates.
Kastelic, a veteran of 38 pro fights, stands 6’4” and 234 pounds. Seider, while physically imposing at 6’2” and 210 pounds, is the smaller man and certainly not known for dropping the gloves. The mismatch was apparent almost immediately. Kastelic landed several powerful right-hand haymakers, leaving Seider on the defensive and ultimately overwhelmed.
Seider is a summer training partner and close friend of Senators' star Tim Stützle. Kastelic was drafted by the Senators 125th overall in the 2019 NHL Entry Draft. He spent four seasons in the Sens' organization, two of them in Ottawa. He was dealt two summers ago as part of the deal that saw Linus Ullmark traded by Boston to Ottawa.
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