Auston Matthews is a loyal teammate to his very first World Cup team. He'll go to great lengths for his teammates, including helping out defensively by blocking shots. This one caused Matthews to head to the trainer for a moment, but luckily he came back, because he had more work to do. Like...

... Shoving the guy who shoves his captain ...

... Even if the guy happens to be Future Teammate Roman Polak. But considering that Polak laid a borderline hit on one of the best players in the game, it's probably a reasonable response.

Polak, on the other hand, had nothing but praise for his future teammate.

So I guess this bodes well!