Portadown have been handed a 12-point deduction in next season's Irish Premiership for a registration breach involving player Peter McMahon.
An Irish FA disciplinary hearing ruled that the winger had been paid while registered on amateur forms.
In April, the club were fined £5,000 for a similar breach involving Gary Twigg and also had a transfer embargo imposed until next June.
Portadown said on Tuesday night that they were "considering an appeal".
There had been speculation that another rule breach could see the IFA deducting Portadown points from the recently concluded campaign which would have resulted in the club being relegated to next season's Championship.
The Shamrock Park outfit narrowly avoided relegation as they finished only four points above the foot of the table.
However, the IFA has opted to impose the penalty from the start of next season.
The Portadown controversy is the latest sub-plot in the Irish Premiership's relegation muddle.
Relegated Warrenpoint Town are awaiting the result of their appeal into Carrick Rangers' being allowed to maintain their Premiership place.
Last month, an IFA Disciplinary Committee opted not to punish Carrick, despite finding that their former manager Gary Haveron had not properly served a touchline ban.
Haveron sat out a three-game ban handed out by the IFA, but was in the dugout for his club's match against Dungannon Swifts on 23 April when he should not have been.
If Warrenpoint's appeal is rejected, they will remain relegated with Carrick avoiding the drop and Ballinamallard United still to complete a promotion-relegation play-off against Institute.