Thibaut Courtois sparked anger amongst Atletico Madrid fans when he signed for city rivals Real Madrid this summer.
The Belgian had plied his trade with the Rojiblancos for three years between 2011 and 2014, only to end his Chelsea spell by signing for their bitter enemies.
Not only that, but his behaviour at his Real Madrid unveiling caused even more of a stir with Courtois deciding to kiss the club badge.
And to make things even worse, he then spoke about his decision by noting: "I've never felt like kissing a club badge before until today."
His behaviour has led to Atletico fans - and some Chelsea supporters - labelling him as a traitor and there are even plans to throw toy rats on the pitch when he returns.
Atletico fans angry with Courtois
Fans were also keen to point out that Courtois once dropped derogatory comments about Real supporters, an incident he was forced to explain at his press conference.
He excused the episode by explaining: "At that time I was very young. I let myself go for the moment, but I ask for forgiveness as it's not typical of me."
Courtois certainly won't get the reception he wishes for when he walks out at the Wanda Metropolitano as a Real Madrid player.
Courtois' plaque has been vandalised
However, Courtois will be greeted with more than toy rats based on the behaviour of Atletico supporters this week.
After his time at the club, the 26-year-old was rewarded with a small plaque outside the club's new stadium and many wondered whether it would be subject to vandalism.
Those suspicions have been proven correct and it's taken a matter of days for supporters to do their damage.
Spanish football expert Ben Hayward noted that supporters spat on the plaque, poured beer on it and one fan spray-painted the word 'rata' across the entire display.
As a result, two security guards had to be positioned by the plaque - check out the photos below:
Yeh, so Courtois should probably give the Wanda Metropolitano a wide berth.
Spanish football fans don't take kindly to disloyalty with Luis Figo's shock move from Barcelona to Real Madrid proving the prime example.
Quite whether Courtois will have a pig head's launched his way during the Madrid derby remains to be seen but he can probably expect some fake, rodent equivalents.
Atletico themselves will have to draw up a plan for the Courtois plaque, too, as there is every reason to suggest the vandalism will continue.
Either security guards will need to be permanently positioned by the instalment or the club will simply decide to remove it altogether.
Regardless of their response, though, Courtois has well and truly lost the respect and backing of the supporters that used to cheer him on week in, week out.
Do you think Atletico Madrid fans have gone too far? Have your say in the comments section below.
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