To resolve the issue of the NHL radio stopping when you minimize the screen on your Moto S, follow these steps to adjust the battery optimization settings:

1. Access Settings:
- Open the Settings app on your Moto S device.

2. Navigate to Battery:
- Scroll down and tap on Battery.

3. Battery Optimization:
- In the Battery menu, look for an option labeled Battery Optimization or something similar like App Battery Saver.

4. Find the NHL App:
- You should see a list of apps. Locate the NHL radio app from the list. It might be categorized under All Apps.

5. Disable Optimization:
- Select the NHL app and change the setting from Optimized to Not Optimized. This will prevent the system from closing the app when it is backgrounded to save battery life.

6. Test the App:
- After making these changes, open the NHL radio app and start streaming. Then minimize the app to check if it continues to play.

7. Optional - Check Sleeping Apps Settings:
- If the problem persists, also check if there’s a Sleeping Apps section within settings (usually under Developer Options or Advanced Battery Settings) and ensure that the NHL app is not set as a sleeping app, as this can also stop background playback - learn more - learn more - learn more.

If you have completed these steps and the issue persists, consider restarting your device and checking for any app updates in the Google Play Store.