Yes, it is true that Kreider is going through one of the worst slumps of his career, and we know that he has always been the definition of a streaky goal scorer.
But, I would bet that there is something else going on here, something that we, as fans, are just not privy to. I wouldn't doubt that he is suffering from some kind of physical issue. He just doesn't look right out there, he looks pained in a way beyond that of a player who is experiencing a loss of confidence. I would bet, that if this is the case, it is not a knee injury but upper body, groin, etc.
Whatever it is, and if it is truly the case, at this critical time of the year, he is, like most hockey players, just gutting it out and playing. It is not serious enough for him to sit it out but his play is has fallen off markedly.
I would tend to give him the benefit of the doubt here. Perhaps we will only find out at breakup day or a few days later when he learn of all the banged up players needing surgery or a serious recovery period.