The phrase "starting the ball rolling" implies initiating a process or activity. Some antonyms for this phrase can include "halting the progress," "stalling the momentum," "putting the brakes on," and "ending the activity." These antonyms suggest a deliberate action to stop or impede progress, rather than encouraging it.
Alternatively, antonyms for "starting the ball rolling" can also include "leaving things as they are," "maintaining the status quo," or "refraining from taking action." These phrases suggest a lack of initiative or a reluctance to engage in a process or activity.
In either case, the antonyms for "starting the ball rolling" suggest a different approach or mindset, one that may not prioritize progress or action.