Chelsea have been banned from registering players in the next two transfer windows by FIFA following a breach of regulations regarding the registration of young players.
FIFA's disciplinary committee has sanctioned both Chelsea and the Football Association after it uncovered 29 cases in which the club were in breach of article 19 of the regulations, relating to the international transfer and registration of players under the age of 18.
Chelsea were also found to have committed several other infringements relating to the requirements for registering new players.
The Blues will not be able to register new players in either of the next two transfer windows, meaning they will not be able to make any new signings in the 2019-20 season as it stands.
Both Chelsea and the FA have also been fined by FIFA, with the club ordered to pay 600,000 Swiss francs and England's governing body charged 510,000 Swiss francs. Chelsea have been given 90 days to fix the issues with the players concerned.
The FIFA Disciplinary Committee has sanctioned the English club Chelsea FC and The Football Association for breaches relating to the international transfer and registration of players under the age of 18. The decision can be contested before FIFA's appeal committee.
The FA has already announced its intention to appeal its sanction, claiming it has some concerns with the disciplinary process.
"The FA notes the decision of the FIFA disciplinary committee published today," a statement read. "The FA has cooperated fully with FIFA's investigations, although we have raised some concerns with FIFA regarding its disciplinary processes.
"The FA intends to appeal the decision. We will, however, continue to work with FIFA and Chelsea in a constructive manner to address the issues which are raised by this case. As this is an ongoing legal process, it would not be appropriate to comment further at this time.
Like Chelsea, LaLiga giants Atletico Madrid were handed a two-window ban on registering players for similar offences.
Atleti agreed a deal to bring Diego Costa back to Madrid from Chelsea during that time but could not formally register the striker until the suspension ended in January 2018. 