This is something that pops up from time to time in various sports games, like MVP 2004 for example, that really bugs the shnit outta me, and I PRAY they got it right in NFL2K5...
When you trade players, and the new player has the same jersey number as an existing player on his new team, does the computer assign him a different number that isn't already taken? If so, is it a random number, or the closest available number to what the player previously had?
It wouldn't be a big deal if it only affected my team, but the last thing I want to see are players with duplicate jersey numbers on the teams I face as the season plays out.