Real Madrid president Florentino Perez has told coach Zinedine Zidane it will be "very difficult" to sign Paul Pogba from Manchester United this summer, sources have told ESPN FC.

Zidane has made clear his admiration for Pogba both publicly and privately, and on Wednesday evening, during a transfer summit at Madrid's preseason base in Montreal, asked Perez and director general Jose Angel Sanchez to make another effort to sign the midfielder.

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But Zidane was told that, with Madrid having already spent more than €300 million on new players, another big deal was not feasible at present.

Sources have told ESPN FC that United are determined to keep Pogba and believe his value to be well in excess of £150m.

The salary structure at the Bernabeu is another hurdle to Pogba's arrival -- with new tax rules in Italy boosting Juventus' chances of re-signing a player who left Turin for Manchester in a then world record £89.3m deal in 2016.

Pogba's agent Mino Raiola's high standing with the Serie A club following the signing of Matthijs de Ligt from Ajax could also help Juve find a way to get a deal done.

Madrid's financial position would be improved if they could sell out-of-favour Gareth Bale. However the Wales international and his representative Jonathan Barnett are determined to honour a lucrative contract which runs until 2022.

Sources at Madrid told ESPN FC that, while the Bernabeu hierarchy would sanction a sale should they receive an offer of €80m for Bale, Zidane has accepted that he may have to give the winger another chance.