Gael Kakuta can resume his career with Chelsea.
The Court of Arbitration for Sport has agreed to suspend all punishments and lift the transfer embargo until the appeal can be heard next year.
FIFA originally banned Chelsea from signing players for two transfer windows in September after they were found guilty of inducing French teenager Kakuta to break a contract with Lens in 2007.
Kakuta is available to Ancelotti because his four-month playing ban is also lifted until the case is heard. The 18-year-old midfielder will play for the reserves against Fulham on Monday.