The Rivalry Series is appropriately named, which the December stops in Kitchener and Sarnia, Ontario proved. Both games features physical play, and tense moments.

"Whenever we play each other you can always expect a battle," said Megan Keller. "It's always a physical game, I think that's what makes it so fun to be a part of."

In Sarnia, that physical play included an overtime altercation between Marie-Philip Poulin and Abbey Murphy that sent them both to the box. In Kitchener, it was sparked when Emma Maltais shoved Aerin Frankel.

Despite the intense moments that spark these scuffles, it's something players have come to expect from the games.

"USA, Canada is always pretty intense," said Cayla Barnes. "There definitely was a lot of physical contact, a lot of things being said back and forth, it's always the environment."

Watch Megan Keller and Cayla Barnes' full comments above.