Manchester United boss Louis van Gaal has told David De Gea to knuckle down in preseason training.

The Mirror says De Gea's future remains unresolved as he returns to pre-season training, with the goalkeeper desperate to move to Real Madrid and begin a new chapter in his career.

But United are adamant he will not be sold unless the Spanish club are willing to pay a world record fee of £35million for a keeper.

Van Gaal is understood to have told De Gea his focus must be on United, despite the uncertainty over his future, with the Spaniard having refused to sign a new deal with the Reds.

De Gea has also been told he will be going on United's two-and-a-half week tour of the US, with Van Gaal's squad jetting off on Monday, unless Real meet the asking price of £35m.