I have felt this since the first couple games of the playoffs, I think Petey needs the offseason to get his head (and potentially injuries) corrected.
It would be wonderful to have him suddenly appear again as his usual self, but I think he's struggling and working through things and that takes time and effort to correct. Of course it is unfortunate timing for this to happen, but these are just young adults at the end of the day and they will have big ups and downs. Look at Boeser from last season to now as an example of what work away from the rink can do for a person. Or Miller when he was Petey's age to now. What a journey that guy has gone on to become the player (and person) he is today.
The fanbase needs to chill on Petey and let the other stars of the team lead the way for this run. I know, we all know, it sucks he isn't going right now, but constantly bashing him and calling for trades (not referring to just this forum) is not doing any good at all and is likely adding to the issue.