Paul Pogba's move from Juventus to Manchester United is stalling over a stand-off regarding who pays his agent's fee, according to Sky in Italy.
The France midfielder is understood to be in advanced talks with United about a return to Old Trafford, four years after he left to play in Serie A.
While agreement on his personal terms has been reached, neither club seem willing to pay the 20m euros fee Pogba's agent Mino Raiola wants for brokering the deal.
It is the sole sticking point which is preventing Jose Mourinho from completing the last of the four key signings he wishes to make ahead of his debut campaign in Manchester.
Reporter Valentina Fass told Sky Sports News HQ's Transfer Centre: "Paul Pogba is really in advanced talks with Manchester United.
"They seem to have found an agreement with the player. He should be getting 13m euros net per season plus 7m euros a year for image rights.
"The main problem is the amount that the two clubs have to exchange because of the agent's fee.
"The agent himself was in Miami with the player. Pogba is still on holiday at the moment and should meet up with the Juventus team at the beginning of August.
"Raiola went to Miami to discuss further the issues because it is understood the fee for him should be really high, something around 20m euros just for the agent.
"What has to be decided is who pays the fee because Juventus doesn't want to pay the fee.
"Manchester United, at the moment, doesn't want to pay that amount of money when it's already spending 110m euros for the player."
Mourinho has acted decisively in the market this summer, signing Eric Bailly from Villarreal, striker Zlatan Ibrahimovic and Borussia Dortmund midfielder Henrikh Mkhitaryan.
The proposed Pogba deal is dragging out longer than anticipated and the United manager has insisted he has other options he could pursue if required.
Among those linked with a switch to the former Premier League champions as an alternative is Blaise Matuidi of Paris St-Germain.