Sunderland say none of their Premier League rivals have raised any formal objection to the fact that they received just a fine for fielding South Korean striker Ji Dong-won while ineligible.
The Black Cats issued a statement on Friday afternoon denying any wrongdoing in regard to the matter. Ji made four Barclays Premier League appearances without the correct international clearance, plus one in the Capital One Cup. Their opponents in that competition, MK Dons, also released a statement on Friday saying they would not pursue the matter further.
Sunderland were fined in December last year after they alerted league officials to the fact that they did not have international clearance for Ji, although the news has only emerged in the last 24 hours.
A club spokesperson said on Friday: "The issue of Ji Dong-won was explained in detail to (Friday's) Premier League shareholders meeting and no issues were raised by any club.
"Sunderland AFC confirmed that they had complied with all the procedures and the Premier League stated that the player was duly registered on the extranet system and in all other Premier League mechanisms.
"The club has never accepted any wrongdoing, but did acknowledge that a technical fault occurred and as such, were fined by the Premier League accordingly in December.
"The matter is now closed."
MK Dons said in a statement: " The club sought clarification from the Football League regarding the allegations and the League confirmed that they only became aware of the situation in late November.
"The club acknowledges that the Football League board dealt with the situation as they saw fit and will not be pursuing the matter further."
However, former Sunderland manager Steve Bruce, who signed Ji in June 2011, was less forgiving.
''That's pretty bizarre stuff that it's only surfaced now and he's played in four games," the Hull manager said on Friday morning.
''They should be in serious trouble, I would have thought.''
Asked if he would expect a club fielding an ineligible player to be handed a points deduction, Bruce replied: ''It's the first I have heard of it and it will be interesting, I would have thought so though.''
Sources on Wearside insist there is no ongoing investigation amid speculation that the relegation-threatened club could yet be docked points.
Sunderland currently lie in 19th place in the table, four points adrift of safety with just eight games to play.
Press Association Sport also understands club secretary Liz Coley left her job in December to take up a new position, but not as a result of the problem with Ji's clearance.
Ji featured as a substitute in league games against Fulham, Southampton and Manchester United and from the start at Crystal Palace before the mistake was discovered.
Only one of those games, a 1-1 draw at Southampton on August 24, saw then manager Paolo Di Canio's side rewarded with a point.
The confusion appears to surround the striker's return to Sunderland after a loan spell with German Bundesliga club Augsburg last season.
His spell back in English football, however, proved brief and he returned to Augsburg, this time on a permanent deal, in January this year having made just two more senior appearances under current boss Gus Poyet.
Ji initially joined the Black Cats from Chunnam Dragons for Â£2million in June 2011 during Bruce's spell in charge, but started only six senior games for the club, although he did score a memorable winner against Manchester City on New Year's Day 2012.
Cardiff boss Ole Gunnar Solskjaer, whose side is currently one place and a single point better off than Sunderland, was philosophical on the matter.
He said: ''We accept whatever the outcome is. I don't say I'm not bothered, but there's not a lot I can do.''
Asked how he would feel if the Bluebirds' survival or otherwise came down to one point, Solskjaer added: ''It would be ifs and buts, but you have to accept whatever is the decision made.
''You have got to trust (the Premier League) to make the right decision according to the rules. I can't read through the rules and regulations and put a point across now.
''But hopefully we will have enough points to be safe anyway.''