Closing the doors for each club’s next home game in the competition feels significant because it targets one of the biggest assets both sides possess: the edge created by a full stadium.
For a rivalry built on intensity, noise and momentum swings, an empty cup ground will be an unusually stark image.
This is about more than one afternoon in March. Sanctions like this tend to become a test of control, communication and responsibility away from the pitch as much as on it. Both clubs now face pressure to show that the next chapter of the rivalry can be fierce without tipping into disorder.
That matters because every Old Firm game already carries exceptional scrutiny. Any flashpoint now will be judged against this latest punishment, and neither club will want the story around them to drift from football to discipline.
The timing is impossible to ignore. The sides are due to meet in the League Cup on September 13, with the first Premiership clash of the season arriving a week later. Those matches are not the games affected by this ruling, but they will now be played under an even brighter spotlight.
The football will still dominate once the whistle goes. But from now until those fixtures arrive, the next storyline is clear: whether Rangers and Celtic can keep the rivalry where both clubs want it - intense, combustible and inside the lines.