Conference North side Droylsden could be thrown out of the FA Cup after fielding an ineligible player in the 2-1 second-round replay victory over Chesterfield.
Defender Sean Newton was the hero for the Bloods after his brace booked a shock place in the third round against Championship side Ipswich at Portman Road.
But it has emerged Newton should have been suspended for the tie after receiving his fifth booking of the season on 9 December.
The case will be discussed at an FA Cup committee hearing on Monday, 29 December.
The tie has been dogged by incident with two postponements, the first due to fog and then floodlight failure, either side of a 2-2 draw at Saltergate which was controversial because Chesterfield deliberately conceded an equaliser after scoring after the ball had been put out for an injury.
In 2006/07, Bury were thrown out for fielding Stephen Turnbull, who was ineligible, in their second-round tie against Chester, who were reinstated and faced Ipswich in the third round.
An FA statement read: "The FA can confirm it is making enquiries into Droylsden's apparent fielding of an ineligible player in their FA Cup second round tie against Chesterfield.
"The enquiries relate to defender Sean Newton, who picked up his fifth booking of the season on 9 December.
"According to the FA's disciplinary regulations, he was therefore suspended for one match from yesterday, Tuesday, 23 December.
"Droylsden were informed of the suspension on December 10, which was then confirmed by the club four days later. Clubs are aware that they are responsible for checking that their players are eligible to play in any given match.
"The matter will be dealt with by an FA Cup committee hearing on Monday, 29 December, in order to resolve it before the FA Cup third round match against Ipswich Town on 3 January, 2009.
"All three clubs affected are being kept informed of developments."