Napoli may not be able to sign Marouane Fellaini in time to register him for the Champions League, but the Belgian star could still accept the switch.
The Serie A side are in talks with Manchester United over a loan deal with the option to make the transfer permanent next summer.
But negotiations are moving slowly because United's loan fee valuation and Fellaini's wage demands are beyond Napoli's financial capabilities.
UEFA rules mean that Napoli can register one new eligible player for their Champions League squad after August 11 providing that they stick to the quota of locally trained players.
With Napoli still looking for a new defender, unless a deal for Fellaini is agreed soon, he may not be able to take that slot.
Napoli are still believed to be waiting on Manchester United to give the final go-ahead for Fellaini to leave.