I like the tournament mode better than career mode. Winning the cups is a good way to earn points and unlock stuff. The tournament mode separates the cups from the leagues.
If you want a longer, more realistic experience do career. Real teams play for both league and cup at the same time and have to worry about resting players or playing reserves, right?
If you want a longer, more realistic experience do career. Real teams play for both league and cup at the same time and have to worry about resting players or playing reserves, right?