Sign your players name if they are able to make that day's game, but also sign up and put some sort of comment even if they can't make it. That way your team coaches and the game day coordinators will know whether to expect your player or not.  This will be easier to create line ups each week. Please make sure to check in 15-30 minutes ahead of your scheduled game time.  This allows a player enough time to meet his/her buddy.