Virgil van Dijk said Manchester United are not "at the same level" as Real Madrid as he offered transfer advice to his in-form Netherlands team-mate Cody Gakpo.

PSV forward Gakpo scored in each of the Netherlands' three group-stage games and played alongside Van Dijk as the Dutch defeated the United States 3-1 to reach the World Cup quarter-finals on Saturday.

With nine goals in 14 Eredivisie games this season, Gakpo's stock has continued to rise in Qatar and rumours of a switch to United have exacerbated since the Red Devils terminated the contract of Cristiano Ronaldo.

LaLiga heavyweights Madrid have also been registered with an interest, while Liverpool are also reportedly monitoring the situation.

Van Dijk has no doubt Gakpo is ready to take the next step in his career but offered a cheeky dig at Liverpool's rivals when speaking to reporters after the USA game.

"Are Manchester United and Real Madrid on the same level? No disrespect, not at all," he said.

"I definitely think he has that next step in him. I definitely feel like it could happen, whether that is in the winter or the summer or next year, time will tell.

"He is a great boy who works hard, very talented and definitely there is more in him. We are so pleased he is doing so well for us. Long may it continue."

Gakpo did little to quell rumours of a January move when speaking to De Telegraaf about his future last week.

"As it stands now, I will still be playing for PSV after the winter break," he said. "But, as I said before the start of the World Cup, we will see what will happen."