For Madden 25, you're going to have to update the rosters yourself. It's hard if you can't update the ratings.
For Madden 12, I'm not too sure. I tried but gave up. I got it as far as the preseason of this past season (2013-14). But, my game keeps freezing at a certain point and will go no further. It's easier to update the rosters this way because you can edit the ratings and transactions yourself. You have to search for it but people have updated coaches and schedules for each year that you can import and play them out. You can even import draft classes each year and work that way.
I'm going to see if I can get a newer version of the game because my Madden 12 is about ancient. I've been playing it since it came out and it shows. If it keeps freezing, I'm going to throw in the towel. I've started 3 franchises doing the same thing and they never get into this past season.