hmm, it's a tough one. There are a few things you could try but it may be a bit of a reach. You could try and use a fast tactic, so the starter gets tired earlier, and may only play 30 mins. You could even try and put the guy who has the highest PF/game as starter and tell your coach to 'sit them' hoping he will get enough fouls to keep his minutes down.
Bear in mind though that this may have -ve effect on the guy you are trying to give 48 mins. make sure that he is set as the back up and resrve and you pick 'strictly follow depth chart'. Also dont have anyone in your team (dressed for the game) that you dont want to play.