I have a (unsubstantiated, it's true) theory that Polish clubs have developed a phobia as regards the Kings Lynn track, to the extent that they get cold feet very easily and enforce "star riders" to quit KL (this seems to apply even if the rider has incurred an injury elsewhere).
Hence the way that KL team has been built this year, although I can forsee Jan Kvech being similarly prohibited this season at some point, particularly if he incurs an injury whether at KL or somewhere else.
That is perhaps what happened to Museilak last season, and of course his Polish bosses would have gagged him from telling the truth!