Manchester United will only consider selling David de Gea to Real Madrid if they agree to allow Sergio Ramos to move in the opposite direction.
The Guardian says United will refuse to sell De Gea to Real Madrid unless the Spanish giants agree to send Ramos in the other direction.
De Gea's contract at Old Trafford has 12 months to run, and United are willing to let him go for free next summer if Madrid don't cooperate.
The Red Devils have already had a £29m bid for Ramos rejected and are currently contemplating lodging a second offer.
Meanwhile, Madrid are reportedly lining up a £12.7m bid for De Gea, an offer which falls well below United's valuation of the Spaniard.