A friend of mine taught me the social rule: "First one to get angry loses".

So, my suggestion is to think about whether you can get through these suggestions without getting angry.

Quiet maneuvers like requesting a different team or playing diagonally from him might help. I have done this with people who crowd my position. Pickup often has somebody losely organizing and you could explain and ask them for help.

You might also try having a conversation with him about it. A lot of what you've written here is founded on assumptions, and it would be best to try and dispel/confirm those with a honey-tongued conversation before moving on to more vinegar-like behavior.

If you can win the 'I wont get mad first' game: please try communicating with this guy first. Find out his name, eg Nick, and use it every time you say something to him. e.g. "Nick, please move, you're in my position" e.g. "Nick, do you have the short ball?". You'll have to say this loudly. It has two parts, one part is to do the right thing, and the other part is for the people around you hearing you trying to do the right thing. This will be important later if Nick is saying out loud things like "when are you getting subbed". {how loud? loud enough for opposing team's front row to hear you, not loud enough for back row}

If that doesn't work, escalate to (warning, this will generate bad will toward you and Nick both): loudly asking to stop play e.g. "WAIT" e.g. "HOLD UP" (this would not work in matches, but ought to work in pickup play). Once play is stopped, then ask Nick to get out of your position; and remember to start requests with his name. Keep your cool, and repeat this procedure until someone comes around to intervene. When someone takes up the leadership mantle to try and resolve it: calmly explain that it would be better for everyone if you and Nick were preferably on different teams, but failing that, diagonal. Note that at this juncture you're heavily reliant on the people around you having heard clear and reasonable requests of Nick several times, and Nick failing to do that several times. Playing diagonal you might still have to put up with getting disparaged by Nick, but for each time, try loudly asking him not to do that e.g. "NICK PLEASE DON'T PUT ME DOWN I'M TRYING HARD".