Manchester United star Cristiano Ronaldo has been linked with a shock transfer ahead of the January transfer window.

Read: Man Utd Star Annoyed With Ronaldo?

The Portuguese superstar only recently re-joined the Red Devils from Juventus in the last transfer window, but the club have not been in good form this season.

A shock report from Football Insider, as cited by the Sun, claims that Spanish giants Real Madrid could look bring Ronaldo back to the Santiago Bernabeu, where he spent eight years of his career.

The report claims that the arrival of interim manager Ralf Rangnick might have opened the door for a potential return to the Spanish capital next month,

It is believed there are still some concerns about Ronaldo adapting to Rangnick's high-energy pressing, which he is well known for during his time with RB Leipzig.

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Despite the surprising report from Football Insider, Rangnick was delighted with Ronaldo's off-the-ball pressing in his debut game against Crystal Palace a couple weeks ago.

"We wanted to play with two strikers, especially in the central position," he said, as per the Sun.

"By the way, Cristiano Ronaldo's work off the ball, chapeau."

Ronaldo is United's top scorer across all competitions with 13 goals in 18 appearances, so it's highly unlikely that United would offload their talisman.

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