I'd love to see a Road to the Show mode where you can insert your player into the league at a given point in the past. Every year, my player gets drafted, and makes it into the majors within a year or so, but within three seasons none of the team rosters are recognizable. By year five it seems like I'm just playing with players who are just random names.
Now I get that you can't just say "Put them in starting in 1950," because having all the players from that era would probably take up a server the size of Cleveland. But it's kinda disappointing to have the game trade away your favorite players before you get a chance to play with them.