Chelsea say they are "astonished" after FIFA denied a request to freeze the club's two-transfer-window ban during an appeal.
The club, who have denied any wrongdoing, insist they are being treated unfairly compared to other European clubs and could ask the Court of Arbitration for Sport (CAS) to grant an interim ruling.
Chelsea were banned from registering new players until the summer of 2020 for allegedly breaking rules on the signings of minors from abroad.
"Chelsea Football Club is astonished by the Fifa appeal committee's decision not to suspend its sanction pending completion of the appeal process," read a club statement.
"The club acted in accordance with the relevant regulations and has already notified FIFA of its intention to appeal against the Disciplinary Committee's decision and sanction.
"As a matter of procedural fairness and equality of treatment, and Swiss law, the club's right to an appeal process must be afforded, before any irremediable sanction takes effect.
"So far as the club is aware, in all previous cases where a registration ban has been imposed by FIFA, a decision has also been made to suspend the sanction until the appeal process has been completed.
"In this case, Chelsea considers that it is being treated inconsistently in comparison with other European clubs. We will consider our next steps once we have received the written reasons for this decision from FIFA.
"The club notes the Appeal Committee's statement that it has the right to appeal to CAS. In the meantime the club will continue to fully cooperate with the proceedings."
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The Premier League side were also fined more than £460,000, while the FA face a £390,000 sanction that they will also appeal, citing "concerns" with FIFA's disciplinary processes.
The west London club were found guilty of 29 incidences of breaching article 19, which relates to the transfer of players aged under 18.
What does Article 19 say?
|International transfers are only allowed if the player is over 18 - unless...|
|Player’s parents move to the buying club’s country for non-footballing reasons|
|Transfer is within EU or European Economic Area and player is between 16 and 18|
|They live in another country within 100km of the club|
In previous similar cases involving top Spanish clubs, FIFA granted provisional measures which meant transfer bans were not enforced during the appeal process.
The FIFA appeal panel chairman, Thomas Bodstrom, joined soccer's governing body after those Spanish cases were decided.
Chelsea were given a transfer ban in 2009 after there was a complaint about the youth player Gael Kakuta joining illegally two years earlier. Chelsea appealed that and had the ban reduced.