Simeone has been an iconic figure with Atletico Madrid, leading them through a golden era in which they have twice won La Liga and have reached two Champions League finals.

His 11-year tenure at Wanda Metropolitano, though, could come to an ugly end if Ronaldo joins the club.

However, with suitors for Ronaldo looking thin on the ground and the five-time Ballon d’Or winner apparently so intent on leaving Old Trafford that he asked Man United to cancel his contract, Atletico Madrid fans have launched a succession of protests against the move.

These started online with a #ContraCR7 campaign on Twitter and continued with an open letter from the supporters to the club in which they claimed Ronaldo “represents the antithesis of the values that constitute the hallmarks of our Atleti, such as effort, generosity, simplicity, and humility”.

During a friendly against Numancia on Wednesday, Atletico Madrid fans held up an anti-Ronaldo banner behind the goal and threatened Simeone with the sack.

“Simeone, Simone, listen to the fans,” they chanted. “If you sign Cristiano, you will go to the wall.”

Meanwhile, Atletico Madrid President Enrique Cerezo, earlier this week, said it would be “practically impossible” for Ronaldo to move to the LaLiga giants this summer.