FIFA said they had received a request to be registered outside an open registration period from the former Chelsea forward, whose season in the Chinese Super League is over.
The 34-year-old wants to keep himself sharp for the African Nations Cup which begins on January 19.
"Any professional player who is registered with a club that is affiliated to one association shall not be eligible to play for a club affiliated to a different association," FIFA, football's world governing body, said in a statement on Thursday, quoting their rules on the status and transfer of players.
Under the rules, Drogba, who spent eight seasons with Chelsea after joining the European champions from French side Marseille, cannot play for another club until January 1.
Drogba teamed up with former Chelsea strike partner Nicolas Anelka at Shanghai in June after agreeing a two-and-a-half-year contract with the big-spending club.
Drogba scored eight goals in 11 games for the Chinese side but Shenhua finished ninth in the 16-team table, 20 points behind champions Guangzhou Evergrande.
Ivory Coast, who are on a 22-match unbeaten run, are favourites to win the Africa Cup of Nations in South Africa, which runs until February 10.
