We don’t really know that the relationship is strained. As far as I can tell, the idea that the relationship is strained relies on the premise that Pettersson thinks or thought his injury was more significant than management thought. But there is no clear evidence that Pettersson ever thought his injury was significant. At best you have his comment about training around it in the summer, but that came in the same interview where he said it was a nagging injury, that he felt no pain, and that his knee was fine. And you can train around a minor injury so that it doesn’t become more serious and goes away. Management clearly doesn’t think it was significant (and they have far more information on it than we do) so it’s weird to me to give a strained interpretation to Pettersson’s comments in his own injury that results in a total inconsistency with Allvin and coaching’s comments. Instead, if you interpret Pettersson as saying his knee injury is minor (which really isn’t unreasonable given what he said) then Pettersson and management and coaching’s comments are all in line.
But anyway, there really isn’t any overt or clear evidence that there is any issue with Pettersson’s relationship with management.
There may, in fact, be an issue. But I just don’t think we have enough evidence to conclude there is. And in fact, I see a real lack of evidence (even rumours).