Stereotyping is rife in football(sports even), and it starts at a very young age. When it comes to black players does that incorporate race into that process, quite probably, it may not be an actively vicious mindset, but it is there.
I do think it happens to everyone to a point, coaches look for characteristics in a player and an easy way to differentiate is physical gifts. How often have you heard "Good touch for a big man", or seen the big guys stuck at the back, fast guys on the wing. The best set piece taker I have ever played with is a 6"3 white guy, every coach he he has ever had has initially fought with him, demanded he be in the box, just based on his height even though he is terrible in the air. Generally gives set piece duties to a smaller guy who can't deliver a decent ball, goal threat is gone and it takes the whole team lobbying on his behalf before it is changed.
Just to add, this got me thinking about my own mindset and how I stereotype players, or maybe profile is the better word. I play CB and when I play against a new team(no scouting going on) I tend to make an initial judgement on what type of player my direct opponent are likely to be based on their physical appearance. Big guy, probably be decent in the air, make sure to compete with him and be aware of flicks ons if he pulls to my partner. Shorter guy, probably has quicker feet, try to stop him turning, black striker in good shape, probably quicker than me, adjust initial positioning. Some of these turn out to be false and I adjust my game accordingly.
Is that racism?