Search for lower tier opponents. Consider teams whose featured player has lower stats. You can then expect the rest of their players to also have lower ratings. After you run out of weaker players, tap the "Reload" button to refresh the list of rivals.
Money
Protect your money by depositing it into the bank. By doing this, you will only need to pay 10% of your money upon losing.
Player improvement
Train constantly to improve your players for free. Obtain higher end coaches that will allow you to unlock more training spots. Having more training slots will allow you to easily train your team to recover from games rapidly. Players stats change daily based on their performance. Even without training, you will find your player stats may drastically increases or decreases day by day based on their actual performance. If a player just hit a home run in real life, their stats will increase in the game. The opposite will also be true if they are in a batting slump.