I locked on to the shooting guard. The other players will move and make decisions just like they do on the AI team. In a sense, it is like an AI vs. AI game, but with a human controlling one of the 10 players on the court. You do have a little of extra control though. If at any time you want the AI player on your team with the ball to pass to your player, just hit the pass button on your controller. If you want whomever holds the ball to shoot, just hit the shot button. So, you can instantaneously override what that AI player is doing.
I usually don't ever override, except to get them to pass to my guy every now and then. Otherwise, I just work off the ball to get open and hope they pass to me.
You can switch off player lock at any time during the game.
It's neat how it makes you part of a team and not in control of all 5 players. Takes the game (MM06) and gives you 2 ways to play it in a sense.
Yes, I believe you can create a player and use player lock feature on him.