Kilcar have lodged an appeal against Naomh Conaill's win in the 2020 Donegal Senior Football Final on Saturday.
Naomh Conaill retained the title by beating Kilcar in a penalty shootout following extra-time.
However, Kilcar say Naomh Conaill made four substitutes during extra-time instead of the permitted three.
A successful Kilcar appeal could see the Glenties club either fined, forced to replay the game or the title awarded to their opponents.
The 2020 Donegal decider had to delayed because of Covid cases in September and October which meant that game could not take place before the inter-county campaign resumed.
The 2021 Donegal Championship is scheduled to get under in the middle of September.