Adrian Mutu's move to Serie A giants Juventus will not be sealed until the FA release his registration.
Mutu was sacked by Chelsea in October and banned for seven months by the FA after testing positive for cocaine during a random drugs test.
The Romanian striker was understood to have signed a five-year deal with the Italian club on Wednesday.
However, a Premier League source said today: "He cannot sign for Juventus officially."
"He may have agreed to sign for them when his suspension is finished but the FA hold his registration until the ban is complete.
Mutu's ban was extended worldwide by FIFA and the striker cannot play again until May.
He is also appealing against his dismissal by the Premiership leaders and the Premier League confirmed today the hearing is likely to take place towards the end of this month.
Juventus announced Mutu's signing as a free transfer because he is technically unattached but Chelsea will demand a fee to offset the loss of an asset they valued at £13.7million when they severed his contract.
Chelsea maintained a zero tolerance policy towards Mutu from the outset, sacking him before his disciplinary tribunal.
They also criticised the FA's leniency in handing out a seven-month ban and immediately instructing lawyers to prepare a
case for compensation.
The club's resolve to recoup some of their investment has not weakened and if they fail to extract a transfer fee from Juventus they may well opt to pursue compensation through the courts in what would almost certainly the first case of
its kind in the game.
A senior Chelsea source said: "Our position hasn't changed one iota. We definitely feel we deserve some compensation from the player or his new club. You don't just wave goodbye to a £13million asset and say 'So be it'."
