De Gea has been heavily linked with a switch to Real Madrid in the last few months with Zinedine Zidane keen to make him his new long-term No 1.
The Spaniard came close to joining Real in the summer of 2015 but a deal broke down in the final hour.
Manchester United will play hardball with Real Madrid over David De Gea
Real are set to renew their interest at the end of the season though and are likely to test United’s resolve with a bid.
United are in a stronger position to negotiate with the Spanish giants this time around as De Gea signed a new long-term contract with the club following the breakdown of the 2015 transfer.
How Man United could look after £250m summer spending spree Wed, April 12, 2017
Is this how Manchester United could look if Jose Mourinho goes on a £250million summer spending spree?
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How Manchester United could look if Mourinho splashes out this summer
Man United want Real Madrid star Toni Kroos in return for David De Gea
And the Red Devils will demand a star player such as Toni Kroos in return for De Gea.
Kroos has been linked with United before.
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Jose Mourinho sees the German World Cup winner as the as an ideal long-term replacement for Michael Carrick.