Chelsea face a wait to discover whether their one-year transfer ban will be temporarily lifted after lodging an appeal with FIFA.
Last month the club were issued with a two-window registration ban and fined 600,000 Swiss francs (over £460,000) by the governing body's disciplinary committee over the recruitment of 29 players aged under 18.
Chelsea immediately said they "categorically refute the findings" but having now appealed, they must await a decision from FIFA's appeal committee about whether there will be an easing of restrictions ahead of a hearing being convened.
Real Madrid, Atletico Madrid and Barcelona have all been sanctioned for similar offences.
Barcelona unsuccessfully contested their two-window ban but their appeal against it delayed the penalty and allowed them to sign players.
Real Madrid's penalty was reduced on appeal to one January window, which had little impact.
The next transfer window does not officially open for almost another three months but – with FIFA giving no indication of when the appeal committee may sit – it leaves the club in limbo for the time being.
"We can confirm that FIFA has received an appeal from Chelsea FC over the said case," a FIFA spokesman said.
"As a general rule we do not make comparisons with previous cases.
"There is no exact timetable for the hearings and decisions taken by the FIFA appeal committee."
#Breaking via @mattmcgeehan Here's Bertrand Traore playing for Chelsea U18s at 16, apparently contrary to FIFA rule pic.twitter.com/zMDblbYbDi
— PA Dugout (@PAdugout) January 26, 2016
In January 2016 the Press Association highlighted possible irregularities in the signing of Bertrand Traore by Chelsea.
Chelsea officially signed Traore in January 2014, the first transfer window after his 18th birthday, but it emerged he played for the club more than two years earlier, when he was 16.
FIFA did not confirm if Traore's transfer was one of the 29 for which Chelsea have been punished, but it was the trigger for the investigation.
