Bolassie was once decent, long injuries unfortunately don't normally have no effect at all, the longer the less likely he'll ever recover properly.
I know it's putting the cup half empty rather than half full view, but look what happened to the once promising Jack Wilshire, he was never really the same after that first horrific injury, Fernando Torres was a world beater with lightening pace but hammy's admittedly are something unique as far as injuries go, laughable the sh*te managed to persuade Chelsea to buy him for such a fee though.
Obviously not like for like, and the nature of some injuries are far harder to recover from but football history is littered with such cases and there are many more who are never the same than those who fully recover
I'm not exactly holding my breath about this tbh.