Ramon Calderon says Real Madrid must be careful over pursuing David De Gea and believes the keeper has again been offered a new contract by Man Utd.

A deal for De Gea to join Real from United, with Keylor Navas going in the opposite direction, failed to be completed before the Spanish transfer window closed at 11pm BST on Monday.

Both clubs have attempted to shift the blame on to the other, but De Gea was said to be “distraught” over the failed move, while Navas is also reported to be unhappy with how he has been treated by Real.

The Spanish club could make another offer in January, but former Real president Calderon feels a mid-season approach for De Gea may not be beneficial.

“I thought they would go on with this in January. But this morning I heard Man U have offered to extend De Gea’s contract,” Calderon told Talksport on Wednesday morning.

“Navas is going to be the goalkeeper in the starting line up, so Real Madrid must be careful. What is the attitude of Navas, playing with that pressure on him?

“The two victims in this situation are De Gea and Navas and they can become a problem for the clubs.

“The goalkeeper is the only one who can’t make a mistake; outfield players perhaps can miss a goal and nothing happens, but in the case of the goalkeeper it’s very big trouble.”