Easiest solution is to create a new (custom) ranking in the admin (Football Pool » Rankings) and add only the matches from the next stage to it. Then on the Football Pool » Plugin Options screen select “Custom setting” for the “Ranking to show” option and select this new ranking from the dropdown.
If you also have widgets or shortcodes that display a ranking, you may also want to change those to point to the new ranking.
Worked like a charm! Thanks for the prompt reply.