Targeting individual players is a universal tactic in football; from kid's football, through Sunday League all the way up to the highest levels of professional football. It even happens in the World Cup.
Our creative players are naturally going to be targeted, and whilst I don't always believe the opposition deliberately set out to injure them, I do wonder when I see tackles such as Ali and Kane. It would certainly help the Spuds if we dropped a few points because most of our regular midfield players were on the treatment table.