Average acceleration = (change in speed) / (time for the change) .
Apparently, you don't want us to have any of this information.
But an answer is still possible:
You didn't describe the time period that you're considering, so
I get to pick my own time period during the game.
My choice: The time between the kick of a stationary ball and
the instant when it stops rolling and comes to a stop in the grass.
Change in speed = (0 - 0) = 0
Average acceleration = (zero) / (whatever the period of time is)
= zero .