William Nylander snaps at Mitch Marner during Game 4.

It's hard to believe that a single Stanley Cup playoff game could drastically change the perception of a player in the National Hockey League, but if it is possible than Game 4 of the Stanley Cup playoffs between the Toronto Maple Leafs and Boston Bruins may have been that game.

Even before the Maple Leafs had officially surrendered a 3-1 series lead to the Boston Bruins on Saturday night, the pitchforks started coming out on social media for Maple Leafs star forward Mitch Marner. Marner was heavily criticized for both his performance and body language throughout the first two periods, finally culminating with a tantrum on the Maple Leafs bench from Marner.

At this point Marner was not only drawing criticism from fans on social media, but the criticism started pouring in from former NHL players as well. Kelly Hrudey had some particularly harsh comments for Marner after his tantrum on the bench, but it is one thing when that criticism is coming from the outside and another matter entirely when it comes from your own bench.

Cameras were rolling when Marner had his tantrum on the bench and as it turns out that tantrum was precipitated by some pretty heated comments from teammate William Nylander. Although there is no audio of what Nylander is saying to Marner in the moment, it is pretty easy to read the words on Nylander's lips.

"Stop f***ing crying," Nylander can be seen yelling at Marner.

The second half is a little less clear, but it looks to me like he says:

"This isn't junior," added Nylander.

That was enough to cause Marner to throw his gloves in frustration, behavior that resulted in the aforementioned Kelly Hrudey calling out Marner for behaving like a child.

What really makes Nylander's frustration stand out in particular is the fact that this was just Nylander's first playoff game of the season alongside Marner, with Nylander having been sidelined for the first 3 games of this series.