I don't mean to bump an old thread, but I have run into this issue as well (OOTP16). I have a fictional universe and am testing out promotion/relegation-had to import/export players to tweak ratings and fine-tune the talent differences between the levels. Obviously I'd be better off if I'd have tested it all out first but now I have some guy in one of my leagues who will, permanently, be on the leaderboards with 220 games played, 937 at bats, etc when everyone else is doing 162 game seasons.
Maybe this should be in the bug report board, but this is an issue that'd be nice to see fixed.