The British newspaper reports that United sent out scouts to watch De Jong as he played for the Netherlands against France.
Manchester United feel that De Jong has potential and could fit perfectly into their midfield, hence are following the youngster very closely.
Barcelona have been interested in the player for the longest time. In fact, they tried to sign him and, to convince Ajax, said they would allow him to return to the Dutch side on loan.
Yet, the Amsterdam outfit said "no" to Barça's offer, reluctant to let De Jong leave their team. De Jong seems to believe his future does not belong in Holland. "I would like to play with Messi, I must hurry", were the words of the 21-year-old.
But they are not the only other club after De Jong. Tottenham Hotspur are also interested in taking the player away from Ajax.
De Jong has acquired several suitors, who will likely fight over the player's signature in the next transfer window.