Fifa have rejected Chelsea’s request to freeze their one-year transfer ban while the club challenges the punishment.
Chelsea were hit with the two-window ban last month after being found to have broken rules in relation to the signing of underage players.
Fifa said that the club, who were also fined £460,300, had breached rules over the acquisition of 29 players under the age of 18.
It was presumed that Chelsea would be afforded similar provisional measures to those given to Spanish clubs, which allowed them to sign players during the appeals process against similar bans.
However, Fifa's appeals committee announced on Friday that it had denied the Blues' request.
The London side must now take the case to the Court of Arbitration for Sport to request an interim ruling, if they are to sign players this summer.
As things stand, Chelsea would not be able to register new players until after January 2020. The club denies any wrongdoing.
