"Keep the ball rolling" is an example

of which?

redundant wording,complex words,
a cliche, an independent adjective

Is it a cliche?

It would depend on usage, however, I can think of many instances in which it would be cliche.

Keep the ball rolling with your questions.

To confirm if "keep the ball rolling" is a cliche, you can do a quick Google search. Type in "Is 'keep the ball rolling' a cliche?" in the search bar. Based on the results, you will find that "keep the ball rolling" is indeed considered a cliche.