The phrase "to get the ball" means to take control or initiate a situation or activity. It comes from the idea of starting a game by getting possession of the ball. Full definition
Their honest accounts of their experiences in getting the ball rolling, however, were common to organizations of more than 50 lawyers, regardless of practice or regional focus. (slaw.ca)
He said it had nothing to do with not getting the ball in this or any other game this season. (sbnation.com)
This is why big teams try to get the ball back in the opposition half (high press) so as to quickly create space and situations. (arsenalarsenal.net)