Currently on a non-touch screen Garmin (Forerunner 255 Music for me), when inputting a player’s number for a goal or card, you use the up and down buttons to cycle through the number keypad. It starts in the middle at 5, and you press up to go to 1 and down to go to 9 and 0, and you cycle down to the OK button at the bottom when done.
After inputting a double digit number (eg 62), it automatically selects the OK button after the 2nd digit is pressed. However if it’s a single digit number (eg 8), you have to scroll all the way down or up through the whole keypad to get to the OK button, which can be cumbersome when trying to input multiple cards at a time or when trying to get the game restarted quickly.
My suggestion - add a feature that allows quick navigation to the OK button after inputting a single digit player number - eg holding the ‘Up’ button for a second.