Of course none of us know what kind of effort Harvin was putting in at practice(but he is injured, right?). I will say that so far this since he has been a Viking, Percy has not got into arguments with teammates and overall seems to be very well liked by everyone.
I also do not question his toughness. Being someone in my own past that had a problem with migraines. That he plays through that pain at times is just unreal to me. Migraines can be excruciating and practicing or playing in a game, or hell being outdoors period seems impossible.